N-CSR

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT

INVESTMENT COMPANIES

Investment Company Act file number             811-04873            

                                     The GAMCO Growth Fund                                    

(Exact name of registrant as specified in charter)

One Corporate Center

                                         Rye, New York 10580-1422                                        

(Address of principal executive offices) (Zip code)

Bruce N. Alpert

Gabelli Funds, LLC

One Corporate Center

                                         Rye, New York 10580-1422                                        

(Name and address of agent for service)

Registrant’s telephone number, including area code:   1-800-422-3554  

Date of fiscal year end:   December 31  

Date of reporting period:   December 31, 2012  

Form N-CSR is to be used by management investment companies to file reports with the Commission not later than 10 days after the transmission to stockholders of any report that is required to be transmitted to stockholders under Rule 30e-1 under the Investment Company Act of 1940 (17 CFR 270.30e-1). The Commission may use the information provided on Form N-CSR in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-CSR, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-CSR unless the Form displays a currently valid Office of Management and Budget (“OMB”) control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to Secretary, Securities and Exchange Commission, 100 F Street, NE, Washington, DC 20549. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Reports to Stockholders.

The Report to Shareholders is attached herewith.

The GAMCO Growth Fund Annual Report — December 31, 2012
	Howard F. Ward, CFA Portfolio Manager

To Our Shareholders,

For the year ended December 31, 2012, the net asset value (“NAV”) per Class AAA Share of The GAMCO Growth Fund increased 15.8% compared with increases of 16.0% and 15.3% for the Standard & Poor’s (“S&P”) 500 Index and the Russell 1000 Growth Index, respectively. See page 3 for additional performance information.

Enclosed are the schedule of investments and financial statements as of December 31, 2012.

Performance Discussion (Unaudited)

The March quarter was the best first quarter for stocks since 1998, amply rewarding investors who stayed with stocks. The rally since October 2011 carried the S&P up nearly 30%, even with a 10% correction from late October to late November 2011. On April 2, just after the end of the March quarter, the S&P 500 closed at 1,419, its highest level since May of 2008.

The economy took a turn for the worse during the second quarter, pressuring stocks and sending Treasury bond yields to record lows. A slowing in job gains domestically, limited progress in addressing the European debt crisis, and signs of weaker than expected growth in China combined to bring the six month equity rally to a halt. When Greece appeared to have reaffirmed its commitment to austerity and the euro, attention shifted to Spain, the eurozone’s fourth largest economy. Spain, unlike Greece, is not viewed as expendable for the euro to survive. At that time, European leaders and the European Central Bank (“ECB”) failed to agree on a comprehensive plan to bring about the needed banking and fiscal union, not to mention political union, seen as critical to regaining investors’ confidence in the euro’s survivability.

Stocks rose during the third quarter. A greater commitment to monetary stimulus in Europe and the U.S., combined with an improving housing market, helped stocks reach levels not seen since early 2008. The Spring correction lasted about two months and amounted to a 10% pullback that ended June 4 with the S&P at 1,278. By the end of September, the market had rallied 13% from the June low and 6% for the quarter, finishing at 1,441. The benchmark index stood just 8% below its all time high of 1,565, set in October of 2007. The Nasdaq market hit a twelve year high in September, although it remained nearly 40% below its high of 2,000 reached during the dot.com bubble.

More often than not, an environment of slow growth and low inflation has historically been favorable for common stocks, and that seems to be the case this year as well. The economic outlook is far from perfect, but housing seems to have turned up, auto sales and production are strong, and consumer spending, the largest contributor to GDP, appears healthier than justified by most headlines. Consumers have continued to spend regardless of macro fears related to the “fiscal cliff” and the slowdowns in Europe and China. Corporations,

however, are putting the brakes on investment spending as they await clarity on taxes, regulations, and the election. They are also reacting to slower growth overseas.

Selected holdings that contributed positively to performance in 2012 were Bank of America Corp (1.0% of net assets as of December 31, 2012), Comcast Corp. – Special Class A (1.6%), Visa Inc. – Class A (1.0%), and Home Depot (2.2%). Some of our weaker performing stocks during the year were Facebook (0.6%), and Joy Global, Occidental Petroleum, and Johnson Controls, all of which were sold prior to year end.

We appreciate your confidence and trust.

Sincerely yours,

Bruce N. Alpert

President

February 22, 2013

2

Comparative Results

Average Annual Returns through December 31, 2012 (a) (Unaudited)							Since Inception (4/10/87)
	1 Year		5 Year		10 Year
Class AAA (GABGX)	15.77	%	(0.69	)%	6.29	%		9.25	%
S&P 500 Index	16.00		1.66		7.10			8.81	(d)
Russell 1000 Growth Index	15.26		3.12		7.52			8.14	(d)
Class A (GGCAX)	15.79		(0.68	)	6.29			9.25
With sales charge (b)	9.13		(1.85	)	5.67			9.00
Class C (GGCCX)	14.92		(1.43	)	5.57			8.96
With contingent deferred sales charge (c)	13.92		(1.43	)	5.57			8.96
Class I (GGCIX)	16.07		(0.45	)	6.41			9.30

In the current prospectus dated April 27, 2012, the expense ratios for Class AAA, A, C and I Shares are 1.48%, 1.48%, 2.23%, and 1.23%, respectively. See page 10 for the expense ratios for the year ended December 31, 2012. Class AAA and Class I Shares do not have a sales charge. The maximum sales charge for Class A and C Shares is 5.75% and 1.00%, respectively.

(a) Returns represent past performance and do not guarantee future results. Total returns and average annual returns reflect changes in share prices, reinvestment of distributions and are net of expenses. Investment returns and the principal value of an investment will fluctuate. When shares are redeemed, they may be worth more or less than their original cost. The Fund imposes a 2% redemption fee on shares sold or exchanged within seven days after the date of purchase. Current performance may be lower or higher than the performance data presented. Visit www.gabelli.com for performance information as of the most recent month end. Investors should carefully consider the investment objectives, risks, charges, and expenses of the Fund before investing. The prospectus contains information about these and other matters and should be read carefully before investing. The Class AAA Share NAVs are used to calculate performance for the periods prior to the issuance of Class A Shares and Class C Shares on December 31, 2003 and Class I Shares on January 11, 2008. The actual performance of the Class C Shares would have been lower due to the additional expenses associated with this class of shares. The actual performance of the Class I Shares would have been higher due to lower expenses related to this class of shares. The S&P 500 Index is a market capitalization weighted index of 500 large capitalization stocks commonly used to represent the U.S. equity market. The Russell 1000 Growth Index measures the performance of the large cap growth segment of the U.S. equity market. Dividends are considered reinvested. You cannot invest directly in an index.

(b) Performance results include the effect of the maximum 5.75% sales charge at the beginning of the period.

(c) Assuming payment of the 1% maximum contingent deferred sales charge imposed on redemptions made within one year of purchase.

(d) S&P 500 Index and Russell 1000 Growth Index since inception performance are as of March 31, 1987.

COMPARISON OF CHANGE IN VALUE OF A $10,000 INVESTMENT IN

THE GAMCO GROWTH FUND (CLASS AAA SHARES) AND S&P 500 INDEX (Unaudited)

* Past performance is not predictive of future results. The performance tables and graph do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or the redemption of Fund shares.

3

The GAMCO Growth Fund Disclosure of Fund Expenses (Unaudited) For the Six Month Period from July 1, 2012 through December 31, 2012 Expense Table

We believe it is important for you to understand the impact of fees and expenses regarding your investment. All mutual funds have operating expenses. As a shareholder of a fund, you incur ongoing costs, which include costs for portfolio management, administrative services, and shareholder reports (like this one), among others. Operating expenses, which are deducted from a fund’s gross income, directly reduce the investment return of a fund. When a fund’s expenses are expressed as a percentage of its average net assets, this figure is known as the expense ratio. The following examples are intended to help you understand the ongoing costs (in dollars) of investing in your Fund and to compare these costs with those of other mutual funds. The examples are based on an investment of $1,000 made at the beginning of the period shown and held for the entire period.

The Expense Table below illustrates your Fund’s costs in two ways:

Actual Fund Return: This section provides information about actual account values and actual expenses. You may use this section to help you to estimate the actual expenses that you paid over the period after any fee waivers and expense reimbursements. The “Ending Account Value” shown is derived from the Fund’s actual return during the past six months, and the “Expenses Paid During Period” shows the dollar amount that would have been paid by an investor who started with $1,000 in the Fund. You may use this information, together with the amount you invested, to estimate the expenses that you paid over the period.

To do so, simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number given for your Fund under the heading “Expenses Paid During Period” to estimate the expenses you paid during this period.

Hypothetical 5% Return: This section provides information about hypothetical account values and                 

hypothetical expenses based on the Fund’s actual expense ratio. It assumes a hypothetical annualized return of 5% before expenses during the period shown. In this case – because the hypothetical return used is not the Fund’s actual return – the results do not apply to your investment and you cannot use the hypothetical account value and expense to estimate the actual ending account balance or expenses you paid for the period. This example is useful in making comparisons of the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in shareholder reports of other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs such as sales charges (loads), redemption fees, or exchange fees, if any, which are described in the Prospectus. If these costs were applied to your account, your costs would be higher. Therefore, the 5% hypothetical return is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. The “Annualized Expense Ratio” represents the actual expenses for the last six months and may be different from the expense ratio in the Financial Highlights which is for the year ended December 31, 2012.

	Beginning Account Value 07/01/12	Ending Account Value 12/31/12	Annualized Expense Ratio	Expenses Paid During Period*
The GAMCO Growth Fund
Actual Fund Return
Class AAA	$1,000.00	$1,062.80	1.49%	$  7.73
Class A	$1,000.00	$1,062.90	1.49%	$  7.73
Class C	$1,000.00	$1,059.00	2.24%	$11.59
Class I	$1,000.00	$1,064.50	1.24%	$  6.43
Hypothetical 5% Return
Class AAA	$1,000.00	$1,017.65	1.49%	$  7.56
Class A	$1,000.00	$1,017.65	1.49%	$  7.56
Class C	$1,000.00	$1,013.88	2.24%	$11.34
Class I	$1,000.00	$1,018.90	1.24%	$  6.29

* Expenses are equal to the Fund’s annualized expense ratio for the last six months multiplied by the average account value over the period, multiplied by the number of days in the most recent fiscal half year (184 days), then divided by 366.

4

Summary of Portfolio Holdings (Unaudited)

The following table presents portfolio holdings as a percent of net assets as of December 31, 2012:

The GAMCO Growth Fund
Information Technology	22.6%
Consumer Discretionary - Other	15.0%
Health Care	12.2%
Consumer Staples	10.6%
Producer Durables	9.4%
Financial Services	9.1%
Consumer Discretionary - Media	8.6%

Energy	5.3%
Materials and Processing	3.8%
U.S. Government Obligations	2.6%
Utilities	1.0%
Other Assets and Liabilities (Net)	(0.2)%
	100.0%

The Fund files a complete schedule of portfolio holdings with the Securities and Exchange Commission (“SEC”) for the first and third quarters of each fiscal year on Form N-Q. Shareholders may obtain this information at www.gabelli.com or by calling the Fund at 800-GABELLI (800-422-3554).The Fund’s Form N-Q is available on the SEC’s website at www.sec.gov and may also be reviewed and copied at the SEC’s Public Reference Room in Washington, DC. Information on the operation of the Public Reference Room may be obtained by calling 800-SEC-0330.

Proxy Voting

The Fund files Form N-PX with its complete proxy voting record for the twelve months ended June 30, no later than August 31 of each year. A description of the Fund’s proxy voting policies, procedures, and how the Fund voted proxies relating to portfolio securities is available without charge, upon request, by (i) calling 800-GABELLI (800-422-3554); (ii) writing to The Gabelli Funds at One Corporate Center, Rye, NY 10580-1422; or (iii) visiting the SEC’s website at www.sec.gov.

We have separated the portfolio manager’s commentary from the financial statements and investment portfolio due to corporate governance regulations stipulated by the Sarbanes-Oxley Act of 2002. We have done this to ensure that the content of the portfolio manager’s commentary is unrestricted. The financial statements and investment portfolio are mailed separately from the commentary. Both the commentary and the financial statements, including the portfolio of investments, will be available on our website at www.gabelli.com.

5

The GAMCO Growth Fund

Schedule of Investments — December 31, 2012

Shares			Cost		Market Value
		COMMON STOCKS — 97.6%
		INFORMATION TECHNOLOGY — 22.6%
	63,000	Apple Inc.	$	18,098,699	$	33,580,890
	345,000	EMC Corp.†		9,030,202		8,728,500
	100,000	Facebook Inc., Cl. A†		3,057,647		2,663,000
	21,200	Google Inc., Cl. A†		11,870,709		15,038,644
	70,000	International Business Machines Corp.		8,086,297		13,408,500
	420,000	Microsoft Corp.		11,250,542		11,226,600
	184,500	QUALCOMM Inc.		10,523,529		11,442,690
		TOTAL INFORMATION TECHNOLOGY		71,917,625		96,088,824
		CONSUMER DISCRETIONARY - OTHER — 15.0%
	3,000	Amazon.com Inc.†		113,658		753,420
	6,000	AutoZone Inc.†		2,271,174		2,126,580
	38,000	Coach Inc.		1,816,174		2,109,380
	58,000	Costco Wholesale Corp.		3,907,609		5,728,660
	150,000	eBay Inc.†		6,469,061		7,653,000
	54,000	Macy’s Inc.		1,637,973		2,107,080
	63,200	NIKE Inc., Cl. B		3,426,989		3,261,120
	40,000	Nordstrom Inc.		1,889,504		2,140,000
	6,900	priceline.com Inc.†		3,948,040		4,286,280
	14,000	Ralph Lauren Corp.		1,298,017		2,098,880
	121,000	Starbucks Corp.		5,090,265		6,488,020
	59,000	The Estee Lauder Companies Inc., Cl. A		2,704,938		3,531,740
	150,000	The Home Depot Inc.		5,501,475		9,277,500
	91,000	The TJX Companies Inc.		2,580,864		3,862,950
	44,400	Tiffany & Co.		2,608,676		2,545,896
	85,000	Wal-Mart Stores Inc.		6,081,117		5,799,550
		TOTAL CONSUMER     DISCRETIONARY - OTHER		51,345,534		63,770,056
		HEALTH CARE — 12.2%
	102,000	Abbott Laboratories		7,086,110		6,681,000
	82,500	Allergan Inc.		6,748,268		7,567,725
	55,000	Amgen Inc.		4,683,901		4,747,600
	66,000	Becton, Dickinson and Co.		5,460,175		5,160,540
	14,000	Biogen Idec Inc.†		2,060,431		2,053,380
	27,000	Celgene Corp.†		2,076,172		2,125,440
	43,400	Gilead Sciences Inc.†		3,274,978		3,187,730
	65,000	Johnson & Johnson		4,326,761		4,556,500
	24,500	Novo Nordisk A/S, Cl. B		1,779,734		3,972,586
	115,000	Roche Holding AG, ADR		4,678,999		5,807,500
	43,000	Shire plc, ADR		4,350,842		3,963,740
	31,000	Varian Medical Systems Inc.†		1,735,966		2,177,440
		TOTAL HEALTH CARE		48,262,337		52,001,181
		CONSUMER STAPLES — 10.6%
	97,000	Beam Inc.		4,532,335		5,925,730
	39,000	Colgate-Palmolive Co.		3,153,780		4,077,060

Shares			Cost		Market Value
	66,000	Diageo plc, ADR	$	5,539,684	$	7,694,280
	89,000	Mead Johnson Nutrition Co.		6,388,363		5,864,210
	60,600	PepsiCo Inc.		3,843,722		4,146,858
	72,000	Philip Morris International Inc.		6,436,857		6,022,080
	265,000	The Coca-Cola Co.		7,527,236		9,606,250
	18,700	Whole Foods Market Inc.		1,094,988		1,707,871
		TOTAL CONSUMER STAPLES		38,516,965		45,044,339
		PRODUCER DURABLES — 9.4%
	43,000	Caterpillar Inc.		4,320,963		3,851,940
	24,100	Cummins Inc.		2,233,137		2,611,235
	37,000	Deere & Co.		3,097,469		3,197,540
	46,000	Eaton Corp. plc		2,387,658		2,493,200
	49,000	Emerson Electric Co.		2,982,868		2,595,040
	17,000	Flowserve Corp.		1,754,744		2,495,600
	110,000	Honeywell International Inc.		4,919,311		6,981,700
	50,000	PACCAR Inc.		2,237,331		2,260,500
	63,000	Union Pacific Corp.		6,597,537		7,920,360
	68,000	United Technologies Corp.		4,450,772		5,576,680
		TOTAL PRODUCER DURABLES		34,981,790		39,983,795
		FINANCIAL SERVICES — 9.1%
	365,000	Bank of America Corp.		2,809,876		4,234,000
	12,400	BlackRock Inc.		2,393,903		2,563,204
	179,900	JPMorgan Chase & Co.		6,368,493		7,910,203
	14,900	MasterCard Inc., Cl. A		4,580,232		7,320,072
	260,000	Morgan Stanley		3,965,865		4,971,200
	57,200	The Goldman Sachs Group Inc.		5,766,224		7,296,432
	29,000	Visa Inc., Cl. A		2,159,515		4,395,820
		TOTAL FINANCIAL SERVICES		28,044,108		38,690,931
		CONSUMER DISCRETIONARY - MEDIA — 8.6%
	73,000	CBS Corp., Cl. B, Non-Voting		1,814,221		2,777,650
	195,000	Comcast Corp., Cl. A, Special		4,803,759		7,010,250
	112,600	DIRECTV†		5,520,173		5,648,016
	94,000	Discovery Communications Inc., Cl. A†		5,180,788		5,967,120
	250,000	News Corp., Cl. A		6,313,026		6,385,000
	74,000	Nielsen Holdings NV†		2,183,113		2,263,660
	123,000	Viacom Inc., Cl. B		5,986,052		6,487,020
		TOTAL CONSUMER     DISCRETIONARY - MEDIA		31,801,132		36,538,716
		ENERGY — 5.3%
	46,000	Cabot Oil & Gas Corp.		1,557,348		2,288,040
	28,000	Continental Resources Inc.†		1,740,244		2,057,720
	53,500	EOG Resources Inc.		5,326,473		6,462,265
	61,000	Pioneer Natural Resources Co.		6,299,043		6,501,990
	76,000	Schlumberger Ltd.		5,260,836		5,266,040
		TOTAL ENERGY		20,183,944		22,576,055

See accompanying notes to financial statements.

6

The GAMCO Growth Fund

Schedule of Investments (Continued) — December 31, 2012

Shares			Cost		Market Value
		COMMON STOCKS (Continued)
		MATERIALS AND PROCESSING — 3.8%
	60,000	E. I. du Pont de Nemours and Co.	$	2,867,127	$	2,698,200
	28,600	Monsanto Co.		1,941,527		2,706,990
	47,000	Precision Castparts Corp.		6,017,696		8,902,740
	14,000	The Sherwin-Williams Co.		2,021,026		2,153,480
		TOTAL MATERIALS AND     PROCESSING		12,847,376		16,461,410
		UTILITIES — 1.0%
	100,000	Verizon Communications Inc.		4,417,988		4,327,000
		TOTAL COMMON STOCKS		342,318,799		415,482,307
Principal Amount
		U.S. GOVERNMENT OBLIGATIONS — 2.6%
	$10,845,000	U.S. Treasury Bills, 0.075% to 0.145%††, 03/14/13 to 06/13/13		10,840,696		10,840,155
		TOTAL INVESTMENTS — 100.2%	$	353,159,495		426,322,462
		Other Assets and Liabilities (Net) — (0.2)%				(810,606	)
		NET ASSETS — 100.0%			$	425,511,856

† Non-income producing security.

†† Represents annualized yield at date of purchase.

ADR American Depositary Receipt

See accompanying notes to financial statements.

7

The GAMCO Growth Fund

Statement of Assets and Liabilities

December 31, 2012

Assets:
Investments, at value (cost $353,159,495)	$	426,322,462
Foreign currency, at value (cost $5)		5
Cash		4,821
Receivable for Fund shares sold		109,189
Dividends receivable		409,089
Prepaid expenses		46,164
Total Assets		426,891,730
Liabilities:
Payable for Fund shares redeemed		694,961
Payable for investment advisory fees		362,354
Payable for distribution fees		89,163
Payable for accounting fees		3,750
Payable for shareholder communications expenses		78,570
Payable for shareholder services fees		77,700
Other accrued expenses		73,376
Total Liabilities		1,379,874
Net Assets
(applicable to 12,224,020 shares outstanding)	$	425,511,856
Net Assets Consist of:
Paid-in capital	$	432,676,328
Undistributed net investment income		945
Accumulated net realized loss on investments and foreign currency transactions		(80,326,864	)
Net unrealized appreciation on investments		73,162,967
Net unrealized depreciation on foreign currency translations		(1,520	)
Net Assets	$	425,511,856

Shares of Beneficial Interest, each at $0.01 par value; unlimited number of shares authorized:
Class AAA:
Net Asset Value, offering, and redemption price per share ($414,691,289 ÷ 11,913,216 shares outstanding)	$34.81
Class A:
Net Asset Value and redemption price per share ($893,579 ÷ 25,663 shares outstanding)	$34.82
Maximum offering price per share (NAV ÷ 0.9425, based on maximum sales charge of 5.75% of the offering price)	$36.94
Class C:
Net Asset Value and offering price per share ($835,302 ÷ 25,572 shares outstanding)	$32.66	(a)
Class I:
Net Asset Value, offering, and redemption price per share ($9,091,686 ÷ 259,569 shares outstanding)	$35.03

(a) Redemption price varies based on the length of time held.

Statement of Operations

For the Year Ended December 31, 2012

Investment Income:
Dividends (net of foreign withholding taxes of $25,876)	$	7,135,449
Interest		2,605
Total Investment Income		7,138,054
Expenses:
Investment advisory fees		4,400,231
Distribution fees - Class AAA		1,074,553
Distribution fees - Class A		2,451
Distribution fees - Class B*		247
Distribution fees - Class C		8,602
Shareholder services fees		469,472
Shareholder communications expenses		181,943
Trustees’ fees		144,888
Custodian fees		56,480
Legal and audit fees		55,805
Registration expenses		49,927
Accounting fees		45,000
Interest expense		566
Miscellaneous expenses		40,135
Total Expenses		6,530,300
Net Investment Income		607,754
Net Realized and Unrealized Gain/(Loss) on Investments and Foreign Currency:
Net realized gain on investments		20,959,675
Net realized gain on foreign currency transactions		8,825
Net realized gain on investments and foreign currency transactions		20,968,500
Net change in unrealized appreciation/depreciation:
on investments		42,804,173
on foreign currency translations		(8,075	)
Net change in unrealized appreciation/depreciation on investments and foreign currency translations		42,796,098
Net Realized and Unrealized Gain/(Loss) on Investments and Foreign Currency		63,764,598
Net Increase in Net Assets Resulting from Operations	$	64,372,352

* Class B shares were fully redeemed and closed on February 2, 2012.

See accompanying notes to financial statements.

8

The GAMCO Growth Fund

Statement of Changes in Net Assets

	Year Ended December 31, 2012			Year Ended December 31, 2011
Operations:
Net investment income	$	607,754		$	1,041,987
Net realized gain on investments and foreign currency transactions		20,968,500			37,243,161
Net change in unrealized appreciation/depreciation on investments and foreign currency translations		42,796,098			(57,824,522	)
Net Increase/(Decrease) in Net Assets Resulting from Operations		64,372,352			(19,539,374	)
Distributions to Shareholders:
Net investment income
Class AAA		(578,029	)		(1,027,291	)
Class A		(1,097	)		(2,149	)
Class I		(36,508	)		(16,023	)
Total Distributions to Shareholders		(615,634	)		(1,045,463	)
Shares of Beneficial Interest Transactions:
Class AAA.		(63,547,002	)		(111,106,419	)
Class A		(18,165	)		(13,595	)
Class B*		(291,682	)		—
Class C		36,632			(61,239	)
Class I		5,399,586			(269,863	)
Net Decrease in Net Assets from Shares of Beneficial Interest Transactions		(58,420,631	)		(111,451,116	)
Redemption Fees		—			30
Net Increase/(Decrease) in Net Assets		5,336,087			(132,035,923	)
Net Assets:
Beginning of period		420,175,769			552,211,692
End of period (including undistributed net investment income of $945 and $0, respectively)	$	425,511,856		$	420,175,769

* Class B Shares were fully redeemed and closed on February 2, 2012.

See accompanying notes to financial statements.

9

The GAMCO Growth Fund

Financial Highlights

Selected data for a share of beneficial interest outstanding throughout each period:

			Income (Loss) from Investment Operations									Distributions															Ratios to Average Net Assets/ Supplemental Data
Period Ended December 31	Net Asset Value, Beginning of Period		Net Investment Income (Loss)(a)			Net Realized and Unrealized Gain (Loss) on Investments			Total from Investment Operations			Net Investment Income			Total Distributions			Redemption Fees (a)(b)		Net Asset Value, End of Period		Total Return†			Net Assets End of Period (in 000’s)		Net Investment Income (Loss)			Operating Expenses			Portfolio Turnover Rate
Class AAA
2012		$30.11		$ 0.04			$   4.71			$   4.75			$(0.05	)		$(0.05	)		$0.00		$34.81		15.8	%		$414,691		0.13	%		1.49	%		41	%
2011		31.39		0.07			(1.28	)		(1.21	)		(0.07	)		(0.07	)		0.00		30.11		(3.8	)		415,416		0.21			1.48			67
2010		28.50		(0.02	)		2.91			2.89			—			—			0.00		31.39		10.1			546,786		(0.06	)		1.47			55
2009		19.56		(0.02	)		8.96			8.94			—			—			0.00		28.50		45.7			575,203		(0.08	)		1.53			83
2008		36.17		(0.09	)		(16.52	)		(16.61	)		—			—			0.00		19.56		(45.9	)		455,357		(0.31	)		1.40			93
Class A
2012		$30.11		$ 0.05			$   4.70			$   4.75			$(0.04	)		$(0.04	)		$0.00		$34.82		15.8	%		$       894		0.15	%		1.49	%		41	%
2011		31.40		0.06			(1.27	)		(1.21	)		(0.08	)		(0.08	)		0.00		30.11		(3.8	)		778		0.18			1.48			67
2010		28.50		(0.01	)		2.91			2.90			—			—			0.00		31.40		10.2			858		(0.05	)		1.47			55
2009		19.57		(0.02	)		8.95			8.93			—			—			0.00		28.50		45.6			1,237		(0.08	)		1.53			83
2008		36.18		(0.08	)		(16.53	)		(16.61	)		—			—			0.00		19.57		(45.9	)		737		(0.29	)		1.40			93
Class C
2012		$28.42		$(0.19	)		$   4.43			$   4.24			—			—			$0.00		$32.66		14.9	%		$       835		(0.61	)%		2.24	%		41	%
2011		29.78		(0.16	)		(1.20	)		(1.36	)		—			—			0.00		28.42		(4.6	)		694		(0.54	)		2.23			67
2010		27.23		(0.21	)		2.76			2.55			—			—			0.00		29.78		9.4			787		(0.80	)		2.22			55
2009		18.84		(0.18	)		8.57			8.39			—			—			0.00		27.23		44.5			1,620		(0.82	)		2.28			83
2008		35.10		(0.28	)		(15.98	)		(16.26	)		—			—			0.00		18.84		(46.3	)		1,467		(1.05	)		2.15			93
Class I
2012		$30.30		$ 0.15			$   4.72			$   4.87			$(0.14	)		$(0.14	)		$0.00		$35.03		16.1	%		$     9,092		0.45	%		1.24	%		41	%
2011		31.60		0.15			(1.29	)		(1.14	)		(0.16	)		(0.16	)		0.00		30.30		(3.6	)		3,013		0.47			1.23			67
2010		28.62		0.05			2.93			2.98			—			—			0.00		31.60		10.4			3,493		0.19			1.22			55
2009		19.60		0.04			8.98			9.02			—			—			0.00		28.62		46.0			3,878		0.17			1.28			83
2008(c)		33.70		0.00	(b)		(14.10	)		(14.10	)		—			—			0.00		19.60		(41.8	)		2,840		0.00	(d)(e)		1.15	(e)		93

† Total return represents aggregate total return of a hypothetical $1,000 investment at the beginning of the period and sold at the end of the period including reinvestment of distributions and does not reflect applicable sales charges. Total return for a period of less than one year is not annualized.

(a) Per share amounts have been calculated using the average shares outstanding method.

(b) Amount represents less than $0.005 per share.

(c) From the commencement of offering Class I Shares on January 11, 2008 through December 31, 2008.

(d) Amount represents less than 0.005%.

(e) Annualized.

See accompanying notes to financial statements.

10

The GAMCO Growth Fund

Notes to Financial Statements

1. Organization. The GAMCO Growth Fund was organized on October 24, 1986 as a Massachusetts business trust and commenced investment operations on April 10, 1987. The Fund is a diversified open-end management investment company registered under the Investment Company Act of 1940, as amended (the “1940 Act”). The Fund’s primary objective is capital appreciation.

2. Significant Accounting Policies. The Fund’s financial statements are prepared in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”), which may require the use of management estimates and assumptions. Actual results could differ from those estimates. The following is a summary of significant accounting policies followed by the Fund in the preparation of its financial statements.

Security Valuation. Portfolio securities listed or traded on a nationally recognized securities exchange or traded in the U.S. over-the-counter market for which market quotations are readily available are valued at the last quoted sale price or a market’s official closing price as of the close of business on the day the securities are being valued. If there were no sales that day, the security is valued at the average of the closing bid and asked prices or, if there were no asked prices quoted on that day, then the security is valued at the closing bid price on that day. If no bid or asked prices are quoted on such day, the security is valued at the most recently available price or, if the Board of Trustees (the “Board”) so determines, by such other method as the Board shall determine in good faith to reflect its fair market value. Portfolio securities traded on more than one national securities exchange or market are valued according to the broadest and most representative market, as determined by Gabelli Funds, LLC (the “Adviser”).

Portfolio securities primarily traded on a foreign market are generally valued at the preceding closing values of such securities on the relevant market, but may be fair valued pursuant to procedures established by the Board if market conditions change significantly after the close of the foreign market, but prior to the close of business on the day the securities are being valued. Debt instruments with remaining maturities of sixty days or less that are not credit impaired are valued at amortized cost, unless the Board determines such amount does not reflect the securities’ fair value, in which case these securities will be fair valued as determined by the Board. Debt instruments having a maturity greater than sixty days for which market quotations are readily available are valued at the average of the latest bid and asked prices. If there were no asked prices quoted on such day, the security is valued using the closing bid price. U.S. government obligations with maturities greater than sixty days are normally valued using a model that incorporates market observable data such as reported sales of similar securities, broker quotes, yields, bids, offers, and reference data. Certain securities are valued principally using dealer quotations.

Securities and assets for which market quotations are not readily available are fair valued as determined by the Board. Fair valuation methodologies and procedures may include, but are not limited to: analysis and review of available financial and non-financial information about the company; comparisons with the valuation and changes in valuation of similar securities, including a comparison of foreign securities with the equivalent U.S. dollar value ADR securities at the close of the U.S. exchange; and evaluation of any other information that could be indicative of the value of the security.

11

The GAMCO Growth Fund

Notes to Financial Statements (Continued)

The inputs and valuation techniques used to measure fair value of the Fund’s investments are summarized into three levels as described in the hierarchy below:

• Level 1 — quoted prices in active markets for identical securities;

• Level 2 — other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.); and

• Level 3 — significant unobservable inputs (including the Fund’s determinations as to the fair value of investments).

A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input both individually and in the aggregate that is significant to the fair value measurement. The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities. The summary of the Fund’s investments in securities by inputs used to value the Fund’s investments as of December 31, 2012 is as follows:

Valuation Inputs*	Investments in Securities (Market Value) Assets
Level 1 - Quoted Prices	$	415,482,307
Level 2 - Other Significant Observable Inputs		10,840,155
Total	$	426,322,462

* Portfolio holdings designated in Level 1 and Level 2 are disclosed individually in the Schedule of Investments (“SOI”). Please refer to the SOI for the industry classifications of these portfolio holdings. Level 2 consists of U.S. Government Obligations.

The Fund did not have transfers between Level 1 and Level 2 during the year ended December 31, 2012. The Fund’s policy is to recognize transfers among Levels as of the beginning of the reporting period.

There were no Level 3 investments held at December 31, 2012 or December 31, 2011.

Additional Information to Evaluate Qualitative Information.

General. The Fund uses recognized industry pricing services – approved by the Board and unaffiliated with the Adviser – to value most of its securities, and uses broker quotes provided by market makers of securities not valued by these and other recognized pricing sources. Several different pricing feeds are received to value domestic equity securities, international equity securities, preferred equity securities, and fixed income securities. The data within these feeds is ultimately sourced from major stock exchanges and trading systems where these securities trade. The prices supplied by external sources are checked by obtaining quotations or actual transaction prices from market participants. If a price obtained from the pricing source is deemed unreliable, prices will be sought from another pricing service or from a broker/dealer that trades that security or similar securities.

Fair Valuation. Fair valued securities may be common and preferred equities, warrants, options, rights, and fixed income obligations. Where appropriate, Level 3 securities are those for which market quotations are not available, such as securities not traded for several days, or for which current bids are not available, or which are restricted as to transfer. Among the factors to be considered to fair value a security are recent prices of comparable securities that are publicly traded, reliable prices of securities not publicly traded, the use of valuation models, current analyst reports, valuing the income or cash flow of the issuer, or cost if the preceding

12

The GAMCO Growth Fund

Notes to Financial Statements (Continued)

factors do not apply. The circumstances of Level 3 securities are frequently monitored to determine if fair valuation measures continue to apply.

The Adviser reports quarterly to the Board the results of the application of fair valuation policies and procedures. These include back testing the prices realized in subsequent trades of these fair valued securities to fair values previously recognized.

Foreign Currency Translations. The books and records of the Fund are maintained in U.S. dollars. Foreign currencies, investments, and other assets and liabilities are translated into U.S. dollars at current exchange rates. Purchases and sales of investment securities, income, and expenses are translated at the exchange rate prevailing on the respective dates of such transactions. Unrealized gains and losses that result from changes in foreign exchange rates and/or changes in market prices of securities have been included in unrealized appreciation/depreciation on investments and foreign currency translations. Net realized foreign currency gains and losses resulting from changes in exchange rates include foreign currency gains and losses between trade date and settlement date on investment securities transactions, foreign currency transactions, and the difference between the amounts of interest and dividends recorded on the books of the Fund and the amounts actually received. The portion of foreign currency gains and losses related to fluctuation in exchange rates between the initial purchase trade date and subsequent sale trade date is included in realized gain/(loss) on investments.

Foreign Securities. The Fund may directly purchase securities of foreign issuers. Investing in securities of foreign issuers involves special risks not typically associated with investing in securities of U.S. issuers. The risks include possible revaluation of currencies, the inability to repatriate funds, less complete financial information about companies, and possible future adverse political and economic developments. Moreover, securities of many foreign issuers and their markets may be less liquid and their prices more volatile than those of securities of comparable U.S. issuers.

Foreign Taxes. The Fund may be subject to foreign taxes on income, gains on investments, or currency repatriation, a portion of which may be recoverable. The Fund will accrue such taxes and recoveries as applicable, based upon its current interpretation of tax rules and regulations that exist in the markets in which it invests.

Securities Transactions and Investment Income. Securities transactions are accounted for on the trade date with realized gain or loss on investments determined by using the identified cost method. Interest income (including amortization of premium and accretion of discount) is recorded on the accrual basis. Premiums and discounts on debt securities are amortized using the effective yield to maturity method. Dividend income is recorded on the ex-dividend date, except for certain dividends from foreign securities that are recorded as soon after the ex-dividend date as the Fund becomes aware of such dividends.

Determination of Net Asset Value and Calculation of Expenses. Certain administrative expenses are common to, and allocated among, various affiliated funds. Such allocations are made on the basis of each fund’s average net assets or other criteria directly affecting the expenses as determined by the Adviser pursuant to procedures established by the Board.

In calculating the NAV per share of each class, investment income, realized and unrealized gains and losses, redemption fees, and expenses other than class specific expenses are allocated daily to each class of shares based upon the proportion of net assets of each class at the beginning of each day. Distribution expenses are borne solely by the class incurring the expense.

13

The GAMCO Growth Fund

Notes to Financial Statements (Continued)

Custodian Fee Credits and Interest Expense. When cash balances are maintained in the custody account, the Fund receives credits which are used to offset custodian fees. The gross expenses paid under the custody arrangement are included in custodian fees in the Statement of Operations with the corresponding expense offset, if any, shown as “Custodian fee credits.” When cash balances are overdrawn, the Fund is charged an overdraft fee equal to 2.00% above the federal funds rate on outstanding balances. This amount, if any, would be included in the Statement of Operations.

Distributions to Shareholders. Distributions to shareholders are recorded on the ex-dividend date. Distributions to shareholders are based on income and capital gains as determined in accordance with federal income tax regulations, which may differ from income and capital gains as determined under GAAP. These differences are primarily due to differing treatments of income and gains on various investment securities held by the Fund and timing differences. These book/tax differences are either temporary or permanent in nature. To the extent these differences are permanent, adjustments are made to the appropriate capital accounts in the period when the differences arise. Permanent differences are primarily due to the tax treatment of currency gains and losses. These reclassifications have no impact on the NAV of the Fund. For the year ended December 31, 2012, reclassifications were made to increase undistributed net investment income by $8,825 and increase accumulated net realized loss on investments and foreign currency transactions by $8,825.

The tax character of distributions paid during the years ended December 31, 2012 and December 31, 2011 was $615,634 and $1,045,463, respectively, of ordinary income.

Provision for Income Taxes. The Fund intends to continue to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”). It is the policy of the Fund to comply with the requirements of the Code applicable to regulated investment companies and to distribute substantially all of its net investment company taxable income and net capital gains. Therefore, no provision for federal income taxes is required.

As of December 31, 2012, the components of accumulated earnings/losses on a tax basis were as follows:

Accumulated capital loss carryforwards	$	(79,518,478	)
Undistributed ordinary income		945
Net unrealized appreciation on investments and foreign currency translations		72,353,061
Total	$	(7,164,472	)

At December 31, 2012, the Fund had net capital loss carryforwards for federal income tax purposes which are available to reduce future required distributions of net capital gains to shareholders. Under the Regulated Investment Company Modernization Act of 2010, the Fund will be permitted to carry forward for an unlimited period capital losses incurred in years beginning after December 22, 2010. In addition, these losses must be utilized prior to the losses incurred in pre-enactment taxable years. As a result of the rule, pre-enactment capital loss carryforwards may have an increased likelihood of expiring unused. Additionally, post enactment capital losses that are carried

14

The GAMCO Growth Fund

Notes to Financial Statements (Continued)

forward will retain their character as either short-term or long-term capital losses rather than being considered all short-term as under previous law.

Capital Loss Carryforward Available through 2016	$	510,304
Capital Loss Carryforward Available through 2017		67,392,145
Capital Loss Carryforward Available through 2018		11,616,029
Total Capital Loss Carryforwards	$	79,518,478

During the year ended December 31, 2012, the Fund utilized capital loss carryforwards of $19,116,507.

At December 31, 2012, the differences between book basis and tax basis unrealized appreciation were primarily due to deferral of losses from wash sales for tax purposes.

The following summarizes the tax cost of investments and the related net unrealized appreciation at December 31, 2012:

	Cost		Gross Unrealized Appreciation		Gross Unrealized Depreciation			Net Unrealized Appreciation
Investments	$	353,967,881	$	77,780,534	$	(5,425,953	)	$	72,354,581

The Fund is required to evaluate tax positions taken or expected to be taken in the course of preparing the Fund’s tax returns to determine whether the tax positions are “more-likely-than-not” of being sustained by the applicable tax authority. Income tax and related interest and penalties would be recognized by the Fund as tax expense in the Statement of Operations if the tax positions were deemed not to meet the more-likely-than-not threshold. For the year ended December 31, 2012, the Fund did not incur any income tax, interest, or penalties. As of December 31, 2012, the Adviser has reviewed all open tax years and concluded that there was no impact to the Fund’s net assets or results of operations. Tax years ended December 31, 2009 through December 31, 2012 remain subject to examination by the Internal Revenue Service and state taxing authorities. On an ongoing basis, the Adviser will monitor the Fund’s tax positions to determine if adjustments to this conclusion are necessary.

3. Investment Advisory Agreement and Other Transactions. The Fund has entered into an investment advisory agreement (the “Advisory Agreement”) with the Adviser which provides that the Fund will pay the Adviser a fee, computed daily and paid monthly, at the annual rate of 1.00% of the value of its average daily net assets. In accordance with the Advisory Agreement, the Adviser provides a continuous investment program for the Fund’s portfolio, oversees the administration of all aspects of the Fund’s business and affairs, and pays the compensation of all Officers and Trustees of the Fund who are affiliated persons of the Adviser.

The Fund pays each Trustee who is not considered an affiliated person an annual retainer of $9,000 plus $2,000 for each Board meeting attended. Each Trustee is reimbursed by the Fund for any out of pocket expenses incurred in attending meetings. All Board committee members receive $500 per meeting attended. The Chairman of the Audit Committee and the Lead Trustee each receive an annual fee of $2,000. The Chairman of the Proxy Voting Committee and Nominating Committee each receives a $1,000 annual fee. A Trustee may receive a single meeting fee, allocated among the participating funds, for attending certain meetings held on behalf of multiple funds. Trustees who are directors or employees of the Adviser or an affiliated company receive no compensation or expense reimbursement from the Fund.

4. Distribution Plan. The Fund’s Board has adopted a distribution plan (the “Plan”) for each class of shares, except for Class I Shares, pursuant to Rule 12b-1 under the 1940 Act. Under the Class AAA, Class A, and

15

The GAMCO Growth Fund

Notes to Financial Statements (Continued)

Class C Share Plans, payments are authorized to G.distributors, LLC (the “Distributor”), an affiliate of the Fund, at annual rates of 0.25%, 0.25%, and 1.00%, respectively, of the average daily net assets of those classes, the annual limitations under each Plan. Such payments are accrued daily and paid monthly.

5. Portfolio Securities. Purchases and sales of securities during the year ended December 31, 2012, other than short-term securities and U.S. Government obligations, aggregated $180,263,370 and $248,105,737, respectively.

6. Transactions with Affiliates. During the year ended December 31, 2012, the Fund paid brokerage commissions on security trades of $4,918 to Gabelli & Company, Inc., an affiliate of the Fund. Additionally, the Distributor retained a total of $821 from investors representing commissions (sales charges and underwriting fees) on sales and redemptions of Fund shares.

The cost of calculating the Fund’s NAV per share is a Fund expense pursuant to the Advisory Agreement. During the year ended December 31, 2012, the Fund paid or accrued $45,000 to the Adviser in connection with the cost of computing the Fund’s NAV.

7. Line of Credit. The Fund participates in an unsecured line of credit of up to $75,000,000 under which it may borrow up to 10% of its net assets from the custodian for temporary borrowing purposes. Borrowings under this arrangement bear interest at the higher of the sum of the overnight LIBOR rate plus 100 basis points or the sum of the federal funds rate plus 100 basis points at the time of borrowing. This amount, if any, would be included in “interest expense” in the Statement of Operations. At December 31, 2012, there were no borrowings outstanding under the line of credit.

The average daily amount of borrowings outstanding under the line of credit during the year ended December 31, 2012 was $9,336 with a weighted average interest rate of 1.24%. The maximum amount borrowed at any time during the year ended December 31, 2012 was $759,000.

8. Shares of Beneficial Interest. The Fund offers four classes of shares – Class AAA Shares, Class A Shares, Class C Shares, and Class I Shares. Class AAA Shares are offered without a sales charge only to investors who acquire them directly from the Distributor, through selected broker/dealers, or the transfer agent. Class I Shares are offered without a sales charge, solely to certain institutions, directly through the Distributor, or brokers that have entered into selling agreements specifically with respect to Class I Shares. Class A Shares are subject to a maximum front-end sales charge of 5.75%. Class C Shares are subject to a 1.00% contingent deferred sales charge for one year after purchase. Class B Shares were fully redeemed and closed on February 2, 2012.

The Fund imposes a redemption fee of 2.00% on all classes of shares that are redeemed or exchanged on or before the seventh day after the date of a purchase. The redemption fee is deducted from the proceeds otherwise payable to the redeeming shareholders and is retained by the Fund as an increase in paid-in capital. The redemption fees retained by the Fund during the years ended December 31, 2012 and December 31, 2011 amounted to $0 and $30, respectively.

16

The GAMCO Growth Fund

Notes to Financial Statements (Continued)

Transactions in shares of beneficial interest were as follows:

	Year Ended December 31, 2012						Year Ended December 31, 2011
	Shares			Amount			Shares			Amount
Class AAA
Shares sold		219,903		$	7,386,673			379,781		$	11,936,622
Shares issued upon reinvestment of distributions		15,929			550,204			32,681			977,060
Shares redeemed		(2,121,086	)		(71,483,879	)		(4,032,952	)		(124,020,101	)
Net decrease		(1,885,254	)	$	(63,547,002	)		(3,620,490	)	$	(111,106,419	)
Class A
Shares sold		16,030		$	525,793			22,779		$	716,511
Shares issued upon reinvestment of distributions		7			320			65			1,937
Shares redeemed		(16,219	)		(544,278	)		(24,314	)		(732,043	)
Net decrease		(182	)	$	(18,165	)		(1,470	)	$	(13,595	)
Class B*
Shares redeemed		(9,658	)	$	(291,682	)		—			—
Net decrease		(9,658	)	$	(291,682	)		—			—
Class C
Shares sold		7,353		$	232,976			5,898		$	171,665
Shares redeemed		(6,217	)		(196,344	)		(7,905	)		(232,904	)
Net increase/(decrease)		1,136		$	36,632			(2,007	)	$	(61,239	)
Class I
Shares sold		217,442		$	7,344,760			44,380		$	1,372,619
Shares issued upon reinvestment of distributions		984			34,189			524			15,751
Shares redeemed		(58,296	)		(1,979,363	)		(55,975	)		(1,658,233	)
Net increase/(decrease)		160,130		$	5,399,586			(11,071	)	$	(269,863	)

* Class B shares were fully redeemed and closed on February 2, 2012.

9. Indemnifications. The Fund enters into contracts that contain a variety of indemnifications. The Fund’s maximum exposure under these arrangements is unknown. However, the Fund has not had prior claims or losses pursuant to these contracts. Management has reviewed the Fund’s existing contracts and expects the risk of loss to be remote.

10. Other Matters. On April 24, 2008, the Adviser entered into a settlement with the SEC to resolve an inquiry regarding prior frequent trading in shares of the GAMCO Global Growth Fund (the “Global Growth Fund”) by one investor who was banned from the Global Growth Fund in August 2002. Under the terms of the settlement, the Adviser, without admitting or denying the SEC’s findings and allegations, paid $16 million (which included a $5 million civil monetary penalty). On the same day, the SEC filed a civil action in the U.S. District Court for the Southern District of New York against the Executive Vice President and Chief Operating Officer of the Adviser, alleging violations of certain federal securities laws arising from the same matter. The officer, who is also an officer of the Global Growth Fund and other funds in the Gabelli/GAMCO complex, including this Fund, denies the allegations and is continuing in his positions with the Adviser and the funds. The settlement by the Adviser did not have, and the resolution of the action against the officer is not expected to have, a material adverse impact on the Adviser or its ability to fulfill its obligations under the Advisory Agreement.

17

The GAMCO Growth Fund

Notes to Financial Statements (Continued)

11. Subsequent Events. Management has evaluated the impact on the Fund of all subsequent events occurring through the date the financial statements were issued and has determined that there were no subsequent events requiring recognition or disclosure in the financial statements.

18

The GAMCO Growth Fund

Report of Independent Registered Public Accounting Firm

To the Board of Trustees and Shareholders of

The GAMCO Growth Fund:

In our opinion, the accompanying statement of assets and liabilities, including the schedule of investments, and the related statements of operations and of changes in net assets and the financial highlights present fairly, in all material respects, the financial position of The GAMCO Growth Fund (hereafter referred to as the “Fund”) at December 31, 2012, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period then ended and the financial highlights for each of the periods presented, in conformity with accounting principles generally accepted in the United States of America. These financial statements and financial highlights (hereafter referred to as “financial statements”) are the responsibility of the Fund’s management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits, which included confirmation of securities at December 31, 2012 by correspondence with the custodian and brokers, provide a reasonable basis for our opinion.

PricewaterhouseCoopers LLP

New York, New York

February 28, 2013

19

The GAMCO Growth Fund

Additional Fund Information (Unaudited)

The business and affairs of the Fund are managed under the direction of the Fund’s Board of Trustees. Information pertaining to the Trustees and officers of the Fund is set forth below. The Fund’s Statement of Additional Information includes additional information about the Fund’s Trustees and is available without charge, upon request, by calling 800-GABELLI (800-422-3554) or by writing to The GAMCO Growth Fund at One Corporate Center, Rye, NY 10580-1422.

Name, Position(s) Address1 and Age	Term of Office and Length of Time Served2	Number of Funds in Fund Complex Overseen by Trustee	Principal Occupation(s) During Past Five Years	Other Directorships Held by Trustee4
INTERESTED TRUSTEES3:
Mario J. Gabelli, CFA Trustee Age: 70	Since 1992	27	Chairman, Chief Executive Officer, and Chief Investment Officer–Value Portfolios of GAMCO Investors, Inc. and Chief Investment Officer–Value Portfolios of Gabelli Funds, LLC, and GAMCO Asset Management Inc.; Director/Trustee or Chief Investment Officer of other registered investment companies in the Gabelli/GAMCO Funds Complex; Chief Executive Officer of GGCP, Inc.	Director of Morgan Group Holdings, Inc. (holding company); Chairman of the Board and Chief Executive Officer of LICT Corp. (multimedia and communication services company); Director of CIBL, Inc. (broadcasting and wireless communications); Director of RLJ Acquisition Inc. (blank check company) (2011-2012)
John D. Gabelli Trustee Age: 68	Since 1995	10	Senior Vice President of Gabelli & Company, Inc.	—
Anthony Torna, Sr. Trustee Age: 86	Since 1987	1	Registered Representative, Maxim Group LLC (2002-2013)	—
INDEPENDENT TRUSTEES5:
Anthony J. Colavita Trustee Age: 77	Since 1989	35	President of the law firm of Anthony J. Colavita, P.C.	—
James P. Conn Trustee Age: 74	Since 1992	19	Former Managing Director and Chief Investment Officer of Financial Security Assurance Holdings Ltd. (insurance holding company) (1992-1998)	Director of First Republic Bank (banking) through January 2008
Dugald A. Fletcher Trustee Age: 83	1989-1996 2000-present	2	President, Fletcher & Company, Inc.	Director of Harris and Harris Group, Inc. (venture capital)
Robert J. Morrissey Trustee Age: 73	Since 2001	6	Partner in the law firm of Morrissey, Hawkins & Lynch	—
Anthony R. Pustorino Trustee Age: 87	Since 1987	13	Certified Public Accountant; Professor Emeritus, Pace University	Director of The LGL Group, Inc. (diversified manufacturing) (2002-2010)
Anthonie C. van Ekris Trustee Age: 78	1987-1989 1992-present	20	Chairman of BALMAC International, Inc. (commodities and futures trading)	—
Salvatore J. Zizza Trustee Age: 67	1987-1996 2000-present	29	Chairman (since 1978) of Zizza & Associates Corp. (financial consulting); Chairman (since 2005) of Metropolitan Paper Recycling, Inc. (recycling); Chairman (since 2009) of E-Corp English (business services)	Chairman of Harbor BioSciences, Inc. (biotechnology); Director of Trans-Lux Corporation (business services); Chairman of Bion Environmental Technologies (technology)

20

The GAMCO Growth Fund

Additional Fund Information (Continued) (Unaudited)

Name, Position(s) Address1 and Age	Term of Office and Length of Time Served2	Principal Occupation(s) During Past Five Years
OFFICERS:
Bruce N. Alpert President, Secretary, and Acting Chief Compliance Officer Age: 61	Since 2003 Since November 2011	Executive Vice President and Chief Operating Officer of Gabelli Funds, LLC since 1988; Officer of all of the registered investment companies in the Gabelli/GAMCO Funds Complex; Director of Teton Advisors, Inc. 1998-2012; Chairman of Teton Advisors, Inc. 2008-2010; President of Teton Advisors, Inc. 1998-2008; Senior Vice President of GAMCO Investors, Inc. since 2008
Agnes Mullady Treasurer Age: 54	Since 2006	President and Chief Operating Officer of the Open-End Fund Division of Gabelli Funds, LLC since September 2010; Senior Vice President of GAMCO Investors, Inc. since 2009; Vice President of Gabelli Funds, LLC since 2007; Officer of all of the registered investment companies in the Gabelli/GAMCO Funds Complex

¹ Address: One Corporate Center, Rye, NY 10580-1422, unless otherwise noted.

² Each Trustee will hold office for an indefinite term until the earliest of (i) the next meeting of shareholders, if any, called for the purpose of considering the election or re-election of such Trustee and until the election and qualification of his or her successor, if any, elected at such meeting, or (ii) the date a Trustee resigns or retires, or a Trustee is removed by the Board of Trustees or shareholders, in accordance with the Fund’s By-Laws and Declaration of Trust. Each officer will hold office for an indefinite term until the date he or she resigns or retires or until his or her successor is elected and qualified.

³ “Interested person” of the Fund as defined in the 1940 Act. Messrs. Gabelli are each considered an “interested person” because of their affiliation with Gabelli Funds, LLC which acts as the Fund’s investment adviser. Mario J. Gabelli and John D. Gabelli are brothers. Mr. Torna is considered an interested person because he was a registered broker during the past fiscal year with a firm to which the Fund Complex (but not the Fund) pays brokerage commissions.

⁴ This column includes only directorships of companies required to report to the SEC under the Securities Exchange Act of 1934, as amended, i.e., public companies, or other investment companies registered under the 1940 Act.

⁵ Trustees who are not interested persons are considered “Independent” Trustees.

2012 TAX NOTICE TO SHAREHOLDERS (Unaudited)

For the year ended December 31, 2012, the Fund paid to shareholders ordinary income distributions (comprised of net investment income) totaling $0.048, $0.043, and $0.138 per share for Class AAA, Class A, and Class I, respectively. For the year ended December 31, 2012, 100% of the ordinary income distribution qualifies for the dividends received deduction available to corporations. The Fund designates 100% of the ordinary income distribution as qualified dividend income pursuant to the Jobs and Growth Tax Relief Reconciliation Act of 2003. The Fund designates 0.04% of the ordinary income distribution as qualified interest income pursuant to the Tax Relief, Unemployment Reauthorization, and Job Creation Act of 2010.

U.S. Government Income:

The percentage of the ordinary income distribution paid by the Fund during the year ended December 31, 2012 which was derived from U.S. Treasury securities was 0.04%. Such income is exempt from state and local tax in all states. However, many states, including New York and California, allow a tax exemption for a portion of the income earned only if a mutual fund has invested at least 50% of its assets at the end of each quarter of the Fund’s fiscal year in U.S. Government securities. The GAMCO Growth Fund did not meet this strict requirement in 2012. The percentage of U.S. Government securities held as of December 31, 2012 was 2.55%. Due to the diversity in state and local tax law, it is recommended that you consult your personal tax adviser as to the applicability of the information provided to your specific situation.

All designations are based on financial information available as of the date of this annual report and, accordingly, are subject to change. For each item, it is the intention of the Fund to designate the maximum amount permitted under the Internal Revenue Code and the regulations thereunder.

21

Gabelli/GAMCO Funds and Your Personal Privacy

Who are we?

The Gabelli/GAMCO Funds are investment companies registered with the Securities and Exchange Commission under the Investment Company Act of 1940. We are managed by Gabelli Funds, LLC, which is affiliated with GAMCO Investors, Inc. GAMCO Investors, Inc. is a publicly held company that has subsidiaries that provide investment advisory or brokerage services for a variety of clients.

What kind of non-public information do we collect about you if you become a fund shareholder?

If you apply to open an account directly with us, you will be giving us some non-public information about yourself. The non-public information we collect about you is:

— Information you give us on your application form. This could include your name, address, telephone number, social security number, bank account number, and other information.

— Information about your transactions with us, any transactions with our affiliates, and transactions with the entities we hire to provide services to you. This would include information about the shares that you buy or redeem. If we hire someone else to provide services — like a transfer agent — we will also have information about the transactions that you conduct through them.

What information do we disclose and to whom do we disclose it?

We do not disclose any non-public personal information about our customers or former customers to anyone other than our affiliates, our service providers who need to know such information, and as otherwise permitted by law. If you want to find out what the law permits, you can read the privacy rules adopted by the Securities and Exchange Commission. They are in volume 17 of the Code of Federal Regulations, Part 248. The Commission often posts information about its regulations on its website, www.sec.gov.

What do we do to protect your personal information?

We restrict access to non-public personal information about you to the people who need to know that information in order to provide services to you or the fund and to ensure that we are complying with the laws governing the securities business. We maintain physical, electronic, and procedural safeguards to keep your personal information confidential.

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GABELLI/GAMCO FAMILY OF FUNDS

VALUE                                                                                   

Gabelli Asset Fund

Seeks to invest primarily in a diversified portfolio of common stocks selling at significant discounts to their private market value. The Fund’s primary objective is growth of capital.

(Multiclass) Team Managed

Gabelli Dividend Growth Fund

Seeks to invest at least 80% of its net assets in dividend paying stocks. (Multiclass)

Portfolio Manager: Barbara G. Marcin, CFA

TETON Westwood Equity Fund

Seeks to invest primarily in the common stock of well seasoned companies that have recently reported positive earnings surprises and are trading below Westwood’s proprietary growth rate estimates. The Fund’s primary objective is capital appreciation.

(Multiclass) Team Managed

FOCUSED VALUE                                                                   

Gabelli Focus Five Fund

Seeks to invest up to 50% of its net assets in the equity securities of five companies with the remaining net assets invested in ten to twenty other companies or in short-term high grade investments or cash and cash equivalents.

(Multiclass) Team Managed 

Gabelli Value Fund

Seeks to invest in securities of companies believed to be undervalued. The Fund’s primary objective is long-term capital appreciation. (Multiclass)                  Team Managed

SMALL CAP                                                                           

Gabelli Small Cap Growth Fund

Seeks to invest primarily in common stock of smaller companies (market capitalizations at the time of investment of $2 billion or less) believed to have rapid revenue and earnings growth potential. The Fund’s primary objective is capital appreciation. (Multiclass)

Portfolio Manager: Mario J. Gabelli, CFA

TETON Westwood SmallCap Equity Fund

Seeks to invest primarily in smaller capitalization equity securities – market caps of $2.5 billion or less. The Fund’s primary objective is long-term capital appreciation.

(Multiclass) Portfolio Manager: Nicholas F. Galluccio

GROWTH                                                                               

GAMCO Growth Fund

Seeks to invest primarily in large cap stocks believed to have favorable, yet undervalued, prospects for earnings growth. The Fund’s primary objective is capital appreciation.

(Multiclass) Portfolio Manager: Howard F. Ward, CFA

GAMCO International Growth Fund

Seeks to invest in the equity securities of foreign issuers with long-term capital appreciation potential. The Fund offers investors global diversification.

(Multiclass) Portfolio Manager: Caesar Bryan

AGGRESSIVE GROWTH                                                        

GAMCO Global Growth Fund

Seeks capital appreciation through a disciplined investment program focusing on the globalization and interactivity of the world’s marketplace. The Fund invests in companies at the forefront of accelerated growth. The Fund’s primary objective is capital appreciation. (Multiclass)

Team Managed

MICRO-CAP                                                                           

TETON Westwood Mighty Mites^SM Fund

Seeks to invest in micro-cap companies that have market capitalizations of $500 million or less. The Fund’s primary objective is long-term capital appreciation. (Multiclass)

Team Managed

EQUITY INCOME                                                                    

Gabelli Equity Income Fund

Seeks to invest primarily in equity securities with above average market yields. The Fund pays monthly distributions and seeks a high level of total return with an emphasis on income. (Multiclass)

Portfolio Manager: Mario J. Gabelli, CFA

TETON Westwood Balanced Fund

Seeks to invest in a balanced and diversified portfolio of stocks and bonds. The Fund’s primary objective is both capital appreciation and current income. (Multiclass)

Team Managed

TETON Westwood Income Fund

Seeks to provide a high level of current income as well as long-term capital appreciation by investing in income producing equity and fixed income securities. (Multiclass)

Portfolio Manager: Barbara G. Marcin, CFA

SPECIALTY EQUITY                                                              

GAMCO Vertumnus Fund

Seeks to invest principally in common stock and convertible securities of domestic and foreign companies. The Fund’s primary objective is total return through a combination of current income and capital appreciation. (Multiclass)

Portfolio Manager: Mario J. Gabelli, CFA

GAMCO Global Opportunity Fund

Seeks to invest in common stock of companies which have rapid growth in revenues and earnings and potential for above average capital appreciation or are undervalued. The Fund’s primary objective is capital appreciation. (Multiclass)

Team Managed

Gabelli SRI Green Fund

Seeks to invest in common and preferred stocks meeting guidelines for social responsibility (avoiding defense contractors and manufacturers of alcohol, abortifacients, gaming, and tobacco products) and sustainability (companies engaged in climate change, energy security and independence, natural resource shortages, organic living, and urbanization). The Fund’s primary objective is capital appreciation. (Multiclass)                             Team Managed

SECTOR                                                                                 

GAMCO Global Telecommunications Fund

Seeks to invest in telecommunications companies throughout the world – targeting undervalued companies with strong earnings and cash flow dynamics. The Fund’s primary objective is capital appreciation.

(Multiclass) Team Managed

Gabelli Gold Fund

Seeks to invest in a global portfolio of equity securities of gold mining and related companies. The Fund’s objective is long-term capital appreciation. Investment in gold stocks is considered speculative and is affected by a variety of worldwide economic, financial, and political factors.

(Multiclass) Portfolio Manager: Caesar Bryan

Gabelli Utilities Fund

Seeks to provide a high level of total return through a combination of capital appreciation and current income.

(Multiclass) Portfolio Manager: Mario J. Gabelli, CFA

MERGER AND ARBITRAGE                                                  

Gabelli ABC Fund

Seeks to invest in securities with attractive opportunities for appreciation or investment income. The Fund’s primary objective is total return in various market conditions without excessive risk of capital loss. (No-load) (Multiclass)

Portfolio Manager: Mario J. Gabelli, CFA

Gabelli Enterprise Mergers and Acquisitions Fund

Seeks to invest in securities believed to be likely acquisition targets within 12–18 months or in arbitrage transactions of publicly announced mergers or other corporate reorganizations. The Fund’s primary objective is capital appreciation. (Multiclass)

Portfolio Manager: Mario J. Gabelli, CFA

CONTRARIAN                                                                        

GAMCO Mathers Fund

Seeks long-term capital appreciation in various market conditions without excessive risk of capital loss. (No-load)

Portfolio Manager: Henry Van der Eb, CFA

Comstock Capital Value Fund

Seeks capital appreciation and current income. The Fund may use either long or short positions to achieve its objective.

(Multiclass) Portfolio Manager: Charles L. Minter

Martin Weiner, CFA

FIXED INCOME                                                                      

TETON Westwood Intermediate Bond Fund

Seeks to invest in a diversified portfolio of bonds with various maturities. The Fund’s primary objective is total return.

(Multiclass) Portfolio Manager: Mark R. Freeman, CFA

CASH MANAGEMENT-MONEY MARKET                              

Gabelli U.S. Treasury Money Market Fund

Seeks to invest exclusively in short-term U.S. Treasury securities. The Fund’s primary objective is to provide high current income consistent with the preservation of principal and liquidity. (No-load)

Co-Portfolio Managers: Judith A. Raneri

Ronald S. Eaker

An investment in the above Money Market Fund is neither insured nor guaranteed by the Federal Deposit Insurance Corporation or any government agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it is possible to lose money by investing in the Fund.

The Funds may invest in foreign securities which involve risks not ordinarily associated with investments in domestic issues, including currency fluctuation, economic, and political risks.

To receive a prospectus, call 800-GABELLI (800-422-3554). Investors should carefully consider the investment objectives, risks, charges, and expenses of a fund before investing. The prospectus contains more information about these and other matters and should be read carefully before investing.

Distributed by G.distributors, LLC, One Corporate Center, Rye, NY 10580.

THE GAMCO GROWTH FUND

One Corporate Center

Rye, New York 10580-1422

t  800-GABELLI (800-422-3554)

f  914-921-5118

e  info@gabelli.com

    GABELLI.COM

Net Asset Value per share available daily

by calling 800-GABELLI after 7:00 P.M.

  BOARD OF TRUSTEES   Mario J. Gabelli, CFA Chairman and Chief Executive Officer, GAMCO Investors, Inc.   Anthony J. Colavita President, Anthony J. Colavita, P.C.   James P. Conn Former Chief Investment Officer, Financial Security Assurance Holdings Ltd.   Dugald A. Fletcher President Fletcher & Company, Inc.   John D. Gabelli Senior Vice President, Gabelli & Company, Inc.   Robert J. Morrissey Partner, Morrissey, Hawkins & Lynch   Anthony R. Pustorino Certified Public Accountant, Professor Emeritus Pace University   Anthony Torna Retired, Maxim Group LLC   Anthonie C. van Ekris Chairman, BALMAC International, Inc.   Salvatore J. Zizza Chairman, Zizza & Associates Corp.   OFFICERS   Bruce N. Alpert President, Secretary, and Acting Chief Compliance Officer   Agnes Mullady Treasurer   DISTRIBUTOR   G.distributors, LLC   CUSTODIAN, TRANSFER AGENT, AND DIVIDEND DISBURSING AGENT   State Street Bank and Trust Company   LEGAL COUNSEL   Skadden, Arps, Slate, Meagher & Flom LLP

This report is submitted for the general information of the shareholders of The GAMCO Growth Fund. It is not authorized for distribution to prospective investors unless preceded or accompanied by an effective prospectus.

GAB406Q412AR

Item 2. Code of Ethics.

(a) The registrant, as of the end of the period covered by this report, has adopted a code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party.

(c) There have been no amendments, during the period covered by this report, to a provision of the code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party, and that relates to any element of the code of ethics description.

(d) The registrant has not granted any waivers, including an implicit waiver, from a provision of the code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party, that relates to one or more of the items set forth in paragraph (b) of this item’s instructions.

Item 3. Audit Committee Financial Expert.

As of the end of the period covered by the report, the registrant’s Board of Trustees has determined that Anthony R. Pustorino is qualified to serve as an audit committee financial expert serving on its audit committee and that he is “independent,” as defined by Item 3 of Form N-CSR.

Item 4. Principal Accountant Fees and Services.

Audit Fees

(a) The aggregate fees billed for each of the last two fiscal years for professional services rendered by the principal accountant for the audit of the registrant’s annual financial statements or services that are normally provided by the accountant in connection with statutory and regulatory filings or engagements for those fiscal years are $34,767 for 2011 and $34,767 for 2012.

Audit-Related Fees

(b) The aggregate fees billed in each of the last two fiscal years for assurance and related services by the principal accountant that are reasonably related to the performance of the audit of the registrant’s financial statements and are not reported under paragraph (a) of this Item are $0 for 2011 and $0 for 2012.

Tax Fees

(c) The aggregate fees billed in each of the last two fiscal years for professional services rendered by the principal accountant for tax compliance, tax advice, and tax planning are $3,625 for 2011 and $3,625 for 2012. Tax fees represent tax compliance services provided in connection with the review of the Registrant’s tax returns.

All Other Fees

(d) The aggregate fees billed in each of the last two fiscal years for products and services provided by the principal accountant, other than the services reported in paragraphs (a) through (c) of this Item are $0 for 2011 and $0 for 2012.

(e)(1) Disclose the audit committee’s pre-approval policies and procedures described in paragraph (c)(7) of Rule 2-01 of Regulation S-X.

Pre-Approval Policies and Procedures. The Audit Committee (“Committee”) of the registrant is responsible for pre-approving (i) all audit and permissible non-audit services to be provided by the independent registered public accounting firm to the registrant and (ii) all permissible non-audit services to be provided by the independent registered public accounting firm to the Adviser, Gabelli Funds, LLC, and any affiliate of Gabelli Funds, LLC (“Gabelli”) that provides services to the registrant (a “Covered Services Provider”) if the independent registered public accounting firm’s engagement related directly to the operations and financial reporting of the registrant. The Committee may delegate its responsibility to pre-approve any such audit and permissible non-audit services to the Chairperson of the Committee, and the Chairperson must report to the Committee, at its next regularly scheduled meeting after the Chairperson’s pre-approval of such services, his or her decision(s). The Committee may also establish detailed pre-approval policies and procedures for pre-approval of such services in accordance with applicable laws, including the delegation of some or all of the Committee’s pre-approval responsibilities to the other persons (other than Gabelli or the registrant’s officers). Pre-approval by the Committee of any permissible non-audit services is not required so long as: (i) the permissible non-audit services were not recognized by the registrant at the time of the engagement to be non-audit services; and (ii) such services are promptly brought to the attention of the Committee and approved by the Committee or Chairperson prior to the completion of the audit.

(e)(2) The percentage of services described in each of paragraphs (b) through (d) of this Item that were approved by the audit committee pursuant to paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X are as follows:

(b) N/A

(c) 100%

(d) N/A

(f) The percentage of hours expended on the principal accountant’s engagement to audit the registrant’s financial statements for the most recent fiscal year that were attributed to work performed by persons other than the principal accountant’s full-time, permanent employees was 0%.

(g) The aggregate non-audit fees billed by the registrant’s accountant for services rendered to the registrant, and rendered to the registrant’s investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant for each of the last two fiscal years of the registrant was $0 for 2011 and $0 for 2012.

(h) The registrant’s audit committee of the board of directors has considered whether the provision of non-audit services that were rendered to the registrant’s investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the investment adviser that provides ongoing services to the registrant that were not pre-approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with maintaining the principal accountant’s independence.

Item 5. Audit Committee of Listed registrants.

Not applicable.

Item 6. Investments.

(a) Schedule of Investments in securities of unaffiliated issuers as of the close of the reporting period is included as part of the report to shareholders filed under Item 1 of this form.

(b) Not applicable.

Item 7. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies.

Not applicable.

Item 8. Portfolio Managers of Closed-End Management Investment Companies.

Not applicable.

Item 9. Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers.

Not applicable.

Item 10. Submission of Matters to a Vote of Security Holders.

There have been no material changes to the procedures by which the shareholders may recommend nominees to the registrant’s Board of Trustees, where those changes were implemented after the registrant last provided disclosure in response to the requirements of Item 407(c)(2)(iv) of Regulation S-K (17 CFR 229.407) (as required by Item 22(b)(15) of Schedule 14A (17 CFR 240.14a-101)), or this Item.

Item 11. Controls and Procedures.

(a) The registrant’s principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the “1940 Act”) (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of the report that includes the disclosure required by this paragraph, based on their evaluation of these controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rules 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934, as amended (17 CFR 240.13a-15(b) or 240.15d-15(b)).

(b) There were no changes in the registrant’s internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant’s second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 12. Exhibits.

(a)(1) Code of ethics, or any amendment thereto, that is the subject of disclosure required by Item 2 is attached hereto.

(a)(2) Certifications pursuant to Rule 30a-2(a) under the 1940 Act and Section 302 of the Sarbanes-Oxley Act of 2002 are attached hereto.

(a)(3) Not applicable.

(b) Certifications pursuant to Rule 30a-2(b) under the 1940 Act and Section 906 of the Sarbanes-Oxley Act of 2002 are attached hereto.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant) The GAMCO Growth Fund

By (Signature and Title)*	/s/ Bruce N. Alpert
	Bruce N. Alpert, Principal Executive Officer

Date 3/8/2013

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)*	/s/ Bruce N. Alpert
	Bruce N. Alpert, Principal Executive Officer

Date 3/8/2013

By (Signature and Title)*	/s/ Agnes Mullady
	Agnes Mullady, Principal Financial Officer and Treasurer

Date 3/8/2013

^* Print the name and title of each signing officer under his or her signature.

EX-99.CODE ETH

GAMCO INVESTORS, INC. and AFFILIATES

Joint Code of Ethics for Chief Executive

And Senior Financial Officers of the Gabelli Funds

Each affiliated registered investment company (each a “Company”) is committed to conducting business in accordance with applicable laws, rules and regulations and the highest standards of business ethics, and to full and accurate disclosure — financial and otherwise — in compliance with applicable law. This Code of Ethics, applicable to each Company’s Chief Executive Officer, President, Chief Financial Officer and Treasurer (or persons performing similar functions) (together, “Senior Officers”), sets forth policies to guide you in the performance of your duties.

As a Senior Officer, you must comply with applicable law. You also have a responsibility to conduct yourself in an honest and ethical manner. You have leadership responsibilities that include creating a culture of high ethical standards and a commitment to compliance, maintaining a work environment that encourages the internal reporting of compliance concerns and promptly addressing compliance concerns.

This Code of Ethics recognizes that the Senior Officers are subject to certain conflicts of interest inherent in the operation of investment companies, because the Senior Officers currently or may in the future serve as Senior Officers of each of the Companies, as officers or employees of the investment advisor to the Companies or service providers thereof (the “Advisor”) and/or affiliates of the Advisor (the “Advisory Group”) and as officers or trustees/directors of other registered investment companies and unregistered investment funds advised by the Advisory Group. This Code of Ethics also recognizes that certain laws and regulations applicable to, and certain policies and procedures adopted by, the Companies or the Advisory Group govern your conduct in connection with many of the conflict of interest situations that arise in connection with the operations of the Companies, including:

— the Investment Company Act of 1940, and the rules and regulation promulgated thereunder by the Securities and Exchange Commission (the “1940 Act”);

— the Investment Advisers Act of 1940, and the rules and regulations promulgated thereunder by the Securities and Exchange Commission (the “Advisers Act”);

— the Code of Ethics adopted by each Company pursuant to Rule 17j-1(c) under the 1940 Act (collectively, the “Trust’s 1940 Act Code of Ethics”);

1

— one or more codes of ethics adopted by the Advisory Group that have been reviewed and approved by those trustees/directors (the “Directors”) of each Company that are not “interested persons” of such Company (the “Independent Directors”) within the meaning of the 1940 Act (the “Advisory Group’s 1940 Act Code of Ethics” and, together with such Company’s 1940 Act Code of Ethics, the “1940 Act Codes of Ethics”);

— the policies and procedures adopted by each Company to address conflict of interest situations, such as procedures under Rule 10f-3, Rule 17a-7 and Rule 17e-1 under the 1940 Act (collectively, the “Conflict Policies”); and

— the Advisory Group’s policies and procedures to address, among other things, conflict of interest situations and related matters (collectively, the “Advisory Policies”).

The provisions of the 1940 Act, the Advisers Act, the 1940 Act Codes of Ethics, the Conflict Policies and the Advisory Policies are referred to herein collectively as the “Additional Conflict Rules”.

This Code of Ethics is different from, and is intended to supplement, the Additional Conflict Rules. Accordingly, a violation of the Additional Conflict Rules by a Senior Officer is hereby deemed not to be a violation of this Code of Ethics, unless and until the Directors shall determine that any such violation of the Additional Conflict Rules is also a violation of this Code of Ethics.

Senior Officers Should Act Honestly and Candidly

Each Senior Officer has a responsibility to each Company to act with integrity. Integrity requires, among other things, being honest and candid. Deceit and subordination of principle are inconsistent with integrity.

Each Senior Officer must:

— act with integrity, including being honest and candid while still maintaining the confidentiality of information where required by law or the Additional Conflict Rules;

— comply with the laws, rules and regulations that govern the conduct of each Company’s operations and report any suspected violations thereof in accordance with the section below entitled “Compliance With Code Of Ethics”; and

— adhere to a high standard of business ethics.

2

Conflicts Of Interest

A conflict of interest for the purpose of this Code of Ethics occurs when your private interests interfere in any way, or even appear to interfere, with the interests of a Company.

Senior Officers are expected to use objective and unbiased standards when making decisions that affect each Company, keeping in mind that Senior Officers are subject to certain inherent conflicts of interest because Senior Officers of a Company also are or may be officers of other Companies and/or the Advisory Group (as a result of which it is incumbent upon you to be familiar with and to seek to comply with the Additional Conflict Rules).

You are required to conduct the business of each Company in an honest and ethical manner, including the ethical handling of actual or apparent conflicts of interest between personal and business relationships. When making any investment, accepting any position or benefits, participating in any transaction or business arrangement or otherwise acting in a manner that creates or appears to create a conflict of interest with respect to each Company where you are receiving a personal benefit, you should act in accordance with the letter and spirit of this Code of Ethics.

If you are in doubt as to the application or interpretation of this Code of Ethics to you as a Senior Officer of a Company, you should make full disclosure of all relevant facts and circumstances to the Chief Compliance Officer of the Advisory Group (the “CCO”) and obtain the approval of the CCO prior to taking action.

Some conflict of interest situations that should always be approved by the CCO, if material, include the following:

— the receipt of any entertainment or non-nominal gift by the Senior Officer, or a member of his or her family, from any company with which a Company has current or prospective business dealings (other than the Advisory Group), unless such entertainment or gift is business related, reasonable in cost, appropriate as to time and place, and not so frequent as to raise any question of impropriety;

— any ownership interest in, or any consulting or employment relationship with, of any of the Companies’ service providers, other than the Advisory Group; or

— a direct or indirect financial interest in commissions, transaction charges or spreads paid by a Company for effecting portfolio transactions or for selling or redeeming shares other than an interest arising from the Senior Officer’s employment by the Advisory Group, such as compensation or equity ownership.

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Disclosures

It is the policy of each Company to make full, fair, accurate, timely and understandable disclosure in compliance with all applicable laws and regulations in all reports and documents that such Company files with, or submits to, the Securities and Exchange Commission or a national securities exchange and in all other public communications made by such Company. As a Senior Officer, you are required to promote compliance with this policy and to abide by such Company’s standards, policies and procedures designed to promote compliance with this policy.

Each Senior Officer must:

— familiarize himself or herself with the disclosure requirements applicable to each Company as well as the business and financial operations of each Company; and

— not knowingly misrepresent, or cause others to misrepresent, facts about any Company to others, including to the Directors, such Company’s independent auditors, such Company’s counsel, any counsel to the Independent Directors, governmental regulators or self-regulatory organizations.

Compliance With Code Of Ethics

If you know of or suspect a violation of this Code of Ethics or other laws, regulations, policies or procedures applicable to the Trust, you must report that information on a timely basis to the CCO or report it anonymously by following the “whistle blower” policies adopted by the Advisory Group from time to time. No one will be subject to retaliation because of a good faith report of a suspected violation.

Each Company will follow these procedures in investigating and enforcing this Code of Ethics, and in reporting on this Code of Ethics:

— the CCO will take all appropriate action to investigate any actual or potential violations reported to him or her;

— violations and potential violations will be reported to the Board of Directors of each affected Company after such investigation;

— if the Board of Directors determines that a violation has occurred, it will take all appropriate disciplinary or preventive action; and

— appropriate disciplinary or preventive action may include a letter of censure, suspension, dismissal or, in the event of criminal or other serious violations of law, notification of the Securities and Exchange Commission or other appropriate law enforcement authorities.

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Waivers Of Code Of Ethics

Except as otherwise provided in this Code of Ethics, the CCO is responsible for applying this Code of Ethics to specific situations in which questions are presented to the CCO and has the authority to interpret this Code of Ethics in any particular situation. The CCO shall take all action he or she considers appropriate to investigate any actual or potential violations reported under this Code of Ethics.

The CCO is authorized to consult, as appropriate, with the chair of the Governance Committee and with counsel to the affected Company, the Advisory Group or the Independent Directors, and is encouraged to do so.

The Board of Directors, the affected Company is responsible for granting waivers of this Code of Ethics, as appropriate. Any changes to or waivers of this Code of Ethics will, to the extent required, be disclosed on Form N-CSR, or otherwise, as provided by Securities and Exchange Commission rules.

Recordkeeping

Each Company will maintain and preserve for a period of not less than six (6) years from the date an action is taken, the first two (2) years in an easily accessible place, a copy of the information or materials supplied to the Boards of Directors pursuant to this Code of Ethics:

— that provided the basis for any amendment or waiver to this Code of Ethics; and

— relating to any violation of this Code of Ethics and sanctions imposed for such violation, together with a written record of the approval or action taken by the relevant Board of Directors.

Confidentiality

All reports and records prepared or maintained pursuant to this Code of Ethics shall be considered confidential and shall be maintained and protected accordingly. Except as otherwise required by law or this Code of Ethics, such matters shall not be disclosed to anyone other than the Independent Trustees and their counsel, the Companies and their counsel, the Advisory Group and its counsel and any other advisors, consultants or counsel retained by the Directors, the Independent Directors or any committee of Directors.

Amendments

This Code of Ethics may not be amended as to any Company except in written form, which is specifically approved by a majority vote of the affected Company’s Directors, including a majority of its Independent Directors.

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No Rights Created

This Code of Ethics is a statement of certain fundamental principles, policies and procedures that govern each of the Senior Officers in the conduct of the Companies’ business. It is not intended to and does not create any rights in any employee, investor, supplier, competitor, shareholder or any other person or entity.

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ACKNOWLEDGMENT FORM

I have received and read the Joint Code of Ethics for Chief Executive and Senior Financial Officers, and I understand its contents. I agree to comply fully with the standards contained in the Code of Ethics and the Company’s related policies and procedures. I understand that I have an obligation to report any suspected violations of the Code of Ethics on a timely basis to the Chief Compliance Officer or report it anonymously by following the “whistle blower” policies adopted by the Advisory Group from time to time.

Printed Name

Signature

Date

7

EX-99.CERT

Certification Pursuant to Rule 30a-2(a) under the 1940 Act and Section 302 of the

Sarbanes-Oxley Act

I, Bruce N. Alpert, certify that:

1. I have reviewed this report on Form N-CSR of The GAMCO Growth Fund;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date:     3/8/2013	/s/ Bruce N. Alpert
	Bruce N. Alpert, Principal Executive Officer

Certification Pursuant to Rule 30a-2(a) under the 1940 Act and Section 302 of the

Sarbanes-Oxley Act

I, Agnes Mullady, certify that:

1. I have reviewed this report on Form N-CSR of The GAMCO Growth Fund;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date:     3/8/2013	/s/ Agnes Mullady
	Agnes Mullady, Principal Financial Officer and Treasurer

EX-99.906CERT

Certification Pursuant to Rule 30a-2(b) under the 1940 Act and Section 906 of the

Sarbanes-Oxley Act

I, Bruce N. Alpert, Principal Executive Officer of The GAMCO Growth Fund (the “Registrant”), certify that:

1. The Form N-CSR of the Registrant (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

Date:     3/8/2013	/s/ Bruce N. Alpert
	Bruce N. Alpert, Principal Executive Officer

I, Agnes Mullady, Principal Financial Officer and Treasurer of The GAMCO Growth Fund (the “Registrant”), certify that:

1. The Form N-CSR of the Registrant (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

Date:     3/8/2013	/s/ Agnes Mullady
	Agnes Mullady, Principal Financial Officer and Treasurer