UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-Q

Quarterly Schedule of Portfolio Holdings of

Registered Management Investment Company

Investment Company Act File Number: 811-00116

The Investment Company of America

(Exact Name of Registrant as specified in charter)

333 South Hope Street,

Los Angeles, California 90071

(Address of principal executive offices)

Registrant's telephone number, including area code: (213) 486-9200

Date of fiscal year end: December 31

Date of reporting period: March 31, 2006

Vincent P. Corti

Capital Research and Management Company

333 South Hope Street

Los Angeles, California 90071

(name and address of agent for service)

Copies to:

Eric A.S. Richards, Esq.

O’Melveny & Myers LLP

400 South Hope Street

Los Angeles, California 90071

(Counsel for the Registrant)

ITEM 1 - Schedule of Investments

[Logo - American Funds®]

The Investment Company of America^®

Investment portfolio

March 31, 2006

unaudited

Common stocks — 83.53%	Shares			Market value (000)
ENERGY — 10.38%
Baker Hughes Inc.		10,875,000		$	743,850
Burlington Resources Inc.		10,440,400			959,577
Chevron Corp.		20,202,278			1,171,126
ConocoPhillips		6,000,000			378,900
ENI SpA		10,680,000			303,954
Exxon Mobil Corp.		7,681,500			467,496
Halliburton Co.		3,020,000			220,520
Marathon Oil Corp.		9,800,000			746,466
Murphy Oil Corp.		4,100,000			204,262
Occidental Petroleum Corp.		1,000,000			92,650
Royal Dutch Shell PLC, Class A (ADR)		17,470,000			1,087,682
Royal Dutch Shell PLC, Class B (ADR)		2,370,498			154,438
Royal Dutch Shell PLC, Class B		833,265			27,111
Schlumberger Ltd.		11,600,000			1,468,212
TOTAL SA		1,820,000			480,251
					8,506,495
MATERIALS — 4.59%
Air Products and Chemicals, Inc.		805,100			54,095
Alcoa Inc.		20,326,400			621,175
Alumina Ltd.		10,000,000			53,026
Barrick Gold Corp. (Canada)		1,114,350			30,334
Barrick Gold Corp.		23,786,250			647,938
Dow Chemical Co.		16,345,950			663,646
E.I. du Pont de Nemours and Co.		3,585,600			151,348
International Paper Co.		4,997,235			172,754
MeadWestvaco Corp.		4,085,000			111,561
Newmont Mining Corp.		9,500,000			492,955
Rio Tinto PLC		9,544,473			484,710
Rohm and Haas Co.		4,000,000			195,480
Weyerhaeuser Co.		1,175,000			85,105
					3,764,127
INDUSTRIALS — 11.48%
3M Co.		1,200,000			90,828
Boeing Co.		8,800,000			685,784
Burlington Northern Santa Fe Corp.		6,500,000			541,645
Caterpillar Inc.		12,850,000			922,759
Cooper Industries, Ltd., Class A		2,500,000			217,250
Cummins Inc.		1,700,000			178,670
Deere & Co.		4,400,000			347,820
FedEx Corp.		1,500,000			169,410
General Dynamics Corp.		6,745,800			431,596
General Electric Co.		42,500,000			1,478,150
Illinois Tool Works Inc.		3,700,000			356,347
Lockheed Martin Corp.		1,060,000			79,638
Mitsubishi Corp.		4,035,000			91,860
Northrop Grumman Corp.		3,400,000			232,186
Parker Hannifin Corp.		2,500,000			201,525
Raytheon Co.		7,399,800			339,207
Siemens AG		2,680,000			250,259
Southwest Airlines Co.		9,000,000			161,910
Tyco International Ltd.		49,160,100			1,321,424
Union Pacific Corp.		2,200,000			205,370
United Parcel Service, Inc., Class B		3,918,700			311,066
United Technologies Corp.		10,190,000			590,714
Waste Management, Inc.		5,550,000			195,915
					9,401,333
CONSUMER DISCRETIONARY — 9.22%
Best Buy Co., Inc.		16,892,700			944,809
Carnival Corp., units		8,165,900			386,819
CBS Corp., Class B		3,250,000			77,935
Clear Channel Communications, Inc.		8,119,700			235,552
Comcast Corp., Class A1		9,357,900			244,803
Ford Motor Co.		2,500,000			19,900
General Motors Corp.		16,950,000			360,527
Harley-Davidson Motor Co.		1,000,000			51,880
Honda Motor Co., Ltd.		702,500			43,503
Kohl’s Corp.1		1,600,000			84,816
Liberty Media Corp., Class A1		16,280,000			133,659
Limited Brands, Inc.2		20,042,743			490,245
Lowe’s Companies, Inc.		23,568,300			1,518,741
McDonald’s Corp.		1,600,000			54,976
Target Corp.		21,475,000			1,116,915
Time Warner Inc.		36,250,000			608,638
TJX Companies, Inc.		11,100,000			275,502
Toyota Motor Corp.		11,650,000			636,336
Viacom Inc., Class B1		3,250,000			126,100
Walt Disney Co.		5,000,000			139,450
					7,551,106
CONSUMER STAPLES — 9.26%
Altria Group, Inc.		54,000,000			3,826,440
Anheuser-Busch Companies, Inc.		3,500,000			149,695
Avon Products, Inc.		9,520,000			296,738
Coca-Cola Co.		6,320,000			264,618
General Mills, Inc.		4,535,000			229,834
H.J. Heinz Co.		2,750,000			104,280
Kraft Foods Inc., Class A		4,350,000			131,849
PepsiCo, Inc.		14,200,000			820,618
Procter & Gamble Co.		1,500,000			86,430
Reynolds American Inc.		4,461,666			470,706
Sara Lee Corp.		8,816,100			157,632
Unilever NV (New York registered)		4,650,000			321,873
UST Inc.		2,000,000			83,200
Walgreen Co.		9,595,000			413,832
Wal-Mart Stores, Inc.		4,750,000			224,390
					7,582,135
HEALTH CARE — 7.59%
Abbott Laboratories		12,400,000		$	526,628
Aetna Inc.		8,200,000			402,948
AstraZeneca PLC (ADR)		5,334,500			267,952
AstraZeneca PLC (Sweden)		4,909,500			247,585
AstraZeneca PLC (United Kingdom)		5,393,900			271,863
Becton, Dickinson and Co.		1,500,000			92,370
Bristol-Myers Squibb Co.		21,278,000			523,652
Cardinal Health, Inc.		2,000,000			149,040
Eli Lilly and Co.		12,045,000			666,088
Guidant Corp.		1,500,000			117,090
HCA Inc.		3,500,000			160,265
Johnson & Johnson		850,000			50,337
McKesson Corp.		2,600,000			135,538
Medco Health Solutions, Inc.1		971,000			55,561
Merck & Co., Inc.		24,250,000			854,327
Novartis AG (ADR)		256,556			14,223
Pfizer Inc		3,000,000			74,760
Roche Holding AG		4,935,000			734,517
Schering-Plough Corp.		16,111,300			305,954
WellPoint, Inc.1		6,300,000			487,809
Wyeth		1,685,000			81,756
					6,220,263
FINANCIALS — 11.29%
Allstate Corp.		1,850,000			96,404
American International Group, Inc.		10,463,900			691,559
Aon Corp.		1,300,000			53,963
Bank of America Corp.		11,834,320			538,935
Berkshire Hathaway Inc., Class A1		3,050			275,568
Capital One Financial Corp.		3,019,300			243,114
Chubb Corp.		3,500,000			334,040
Citigroup Inc.		24,260,000			1,145,800
Fannie Mae		25,865,600			1,329,492
Freddie Mac		5,750,000			350,750
Hartford Financial Services Group, Inc.		2,250,000			181,237
HSBC Holdings PLC (ADR)		1,079,588			90,448
HSBC Holdings PLC (United Kingdom)		17,037,111			285,741
J.P. Morgan Chase & Co.		18,836,200			784,339
Lloyds TSB Group PLC		40,000,000			382,708
Marsh & McLennan Companies, Inc.		7,900,000			231,944
National City Corp.		2,430,000			84,807
U.S. Bancorp		11,250,000			343,125
Washington Mutual, Inc.		25,400,000			1,082,548
Wells Fargo & Co.		9,330,000			595,907
XL Capital Ltd., Class A		2,000,000			128,220
					9,250,649
INFORMATION TECHNOLOGY — 11.08%
Altera Corp.1		5,500,000			113,520
Analog Devices, Inc.		4,250,000			162,732
Applied Materials, Inc.		18,450,000			323,059
Automatic Data Processing, Inc.		5,875,000			268,370
Canon, Inc.		1,800,000			119,113
Cisco Systems, Inc.1		31,870,400			690,632
Electronic Data Systems Corp.		1,900,000			50,977
First Data Corp.		2,600,000			121,732
Google Inc., Class A1		450,000			175,500
Hewlett-Packard Co.		22,150,000			728,735
Intel Corp.		7,390,000			142,997
International Business Machines Corp.		9,945,000			820,164
KLA-Tencor Corp.		1,825,000			88,257
Linear Technology Corp.		6,350,000			222,758
Maxim Integrated Products, Inc.		6,300,000			234,045
Micron Technology, Inc.1		10,000,000			147,200
Microsoft Corp.		49,280,000			1,340,909
Motorola, Inc.		3,201,475			73,346
Nokia Corp. (ADR)		9,314,900			193,005
Nokia Corp., Class A		3,060,150			63,353
Oracle Corp.1		74,960,100			1,026,204
Sabre Holdings Corp., Class A		5,509,680			129,643
Samsung Electronics Co., Ltd.		670,000			434,438
Solectron Corp.1		11,000,000			44,000
Sun Microsystems, Inc.1		25,010,000			128,301
Taiwan Semiconductor Manufacturing Co. Ltd.		155,092,208			307,199
Texas Instruments Inc.		22,570,200			732,854
Xilinx, Inc.		7,650,000			194,769
					9,077,812
TELECOMMUNICATION SERVICES — 5.72%
ALLTEL Corp.		2,942,750			190,543
AT&T Inc.		73,755,497			1,994,349
BellSouth Corp.		33,800,000			1,171,170
Qwest Communications International Inc.1		26,829,700			182,442
Sprint Nextel Corp.		25,685,000			663,700
Telefónica, SA		8,767,200			137,616
Verizon Communications Inc.		4,183,200			142,480
Vodafone Group PLC		98,500,000			206,287
					4,688,587
UTILITIES — 2.01%
American Electric Power Co., Inc.		1,000,000			34,020
Dominion Resources, Inc.		7,131,912			492,316
Duke Energy Corp.		5,000,000			145,750
Exelon Corp.		5,275,500			279,074
FirstEnergy Corp.		1,138,500			55,672
FPL Group, Inc.		3,800,000			152,532
PPL Corp.		2,300,000			67,620
Public Service Enterprise Group Inc.		6,500,000			416,260
					1,643,244
MISCELLANEOUS — 0.91%
Other common stocks in initial period of acquisition					745,146
Total common stocks (cost: $46,537,893,000)					68,430,897
Convertible securities — 0.28%		Shares or principal amount			Market value (000	)
FINANCIALS — 0.12%
Fannie Mae 5.375% convertible preferred 2049		970		$	92,756
TELECOMMUNICATION SERVICES — 0.16%
Qwest Communications International Inc. 3.50% convertible debenture 2025	$	100,000,000			133,375
Total convertible securities (cost: $190,489,000)					226,131
Bonds & notes — 0.48%		Principal amount (000	)
CONSUMER DISCRETIONARY — 0.05%
General Motors Corp. 7.125% 2013	$	25,630			19,223
General Motors Corp. 7.20% 2011		28,708			22,536
					41,759
MORTGAGE-BACKED OBLIGATIONS3— 0.43%
Fannie Mae 6.00% 2017		110,426			111,922
Fannie Mae 6.00% 2017		139,511			141,401
Fannie Mae 6.50% 2017		98,487			100,749
					354,072
Total bonds & notes (cost: $393,430,000)					395,831
Short-term securities — 15.63%
3M Co. 4.65% due 5/19/2006		75,000			74,543
AIG Funding Inc. 4.50% due 4/7/2006		25,000			24,982
American General Finance Corp. 4.49% due 4/5/2006		30,000			29,985
International Lease Finance Corp. 4.55%-4.725% due 4/12-5/19/2006		253,700			252,592
American Express Credit Corp. 4.50%-4.65% due 4/5-5/15/2006		125,000			124,540
Anheuser-Busch Companies, Inc. 4.40%-4.62% due 4/12-6/1/20064		105,000			104,557
Atlantic Industries 4.47%-4.56% due 4/10-4/25/20064		200,000			199,568
Coca-Cola Co. 4.66% due 5/31/2006		100,000			99,218
Bank of America Corp. 4.52%-4.66% due 4/24-5/10/2006		300,000			298,880
BellSouth Corp. 4.56% due 5/1/20064		75,000			74,705
CAFCO, LLC 4.58%-4.79% due 4/28-6/9/20064		300,000			298,073
Citigroup Funding Inc. 4.60%-4.62% due 4/24/2006		50,000			49,853
Caterpillar Financial Services Corp. 4.47%-4.59% due 4/3-4/17/2006		101,300			101,227
Chevron Funding Corp. 4.47%-4.58% due 4/28/2006		100,000			99,661
Clipper Receivables Co., LLC 4.52%-4.77% due 4/26-5/31/20064		350,000			347,900
Concentrate Manufacturing Co. of Ireland 4.52%-4.73% due 4/4-5/5/20064		165,000			164,539
DuPont (E.I.) de Nemours & Co. 4.63%-4.66% due 5/8/20064		75,000			74,632
Edison Asset Securitization LLC 4.65% due 5/22/20064		50,000			49,659
General Electric Capital Corp. 4.51%-4.72% due 4/5-5/3/2006		175,000			174,469
General Electric Capital Services 4.45%-4.55% due 4/10/2006		100,000			99,885
Fannie Mae 4.52%-4.675% due 5/10-6/14/2006		325,600			323,126
FCAR Owner Trust I 4.63%-4.77% due 5/3-5/24/2006		100,000			99,449
Federal Farm Credit Banks 4.29%-4.68% due 4/4-6/26/2006		460,000			457,133
Federal Home Loan Bank 4.34%-4.755% due 4/5-6/28/2006		1,754,800			1,745,528
Freddie Mac 4.36%-4.69% due 4/10-6/20/2006		1,406,900			1,400,348
Gannett Co. 4.54% due 4/25/20064		100,000			99,684
Harvard University 4.52% due 4/24/2006		20,000			19,940
Hershey Co. 4.46%-4.61% due 4/3-5/2/20064		75,000			74,819
HSBC Finance Corp. 4.45%-4.65% due 4/4-4/24/2006		325,000			324,579
IBM Capital Inc. 4.69%-4.70% due 4/26-6/9/20064		100,000			99,242
International Bank for Reconstruction and Development 4.42%-4.50% due 4/5-4/28/2006		275,000			274,436
J.P. Morgan Chase & Co. 4.52%-4.60% due 4/7/2006		100,000			99,926
Park Avenue Receivables Co., LLC 4.54%-4.74% due 4/19/20064		150,000			149,653
Preferred Receivables Funding Corp. 4.71%-4.75% due 5/12/20064		100,000			99,448
McCormick & Co., Inc. 4.68% due 5/31/20064		25,000			24,805
Medtronic Inc. 4.56% due 5/5/20064		20,000			19,915
NetJets Inc. 4.53%-4.77% due 4/5-6/5/20064		90,000			89,527
Pfizer Investment Capital PLC 4.56% due 5/16/20064		75,000			74,550
Pitney Bowes Inc. 4.70% due 4/24/20064		50,000			49,843
Private Export Funding Corp. 4.37%-4.65% due 4/5-6/1/20064		153,000			152,610
Procter & Gamble Co. 4.51%-4.69% due 4/3-4/28/20064		170,000			169,754
Suntrust Bank 4.57% due 5/8/2006		100,000			99,982
Three Pillars Funding LLC 4.84% due 6/22/20064		35,000			34,618
Tennessee Valley Authority 4.45%-4.655% due 4/13-6/15/2006		157,500			156,561
U.S. Treasury Bills 4.105%-4.596% due 4/6-6/22/2006		3,020,000			3,005,454
Variable Funding Capital Corp. 4.45%-4.73% due 4/3-5/17/20064		355,000			353,990
Wal-Mart Stores Inc. 4.41%-4.75% due 4/4-6/13/20064		220,000			218,426
Wells Fargo & Co. 4.66%-4.77% due 5/3-5/30/2006		325,000			324,995
Wm. Wrigley Jr. Co. 4.41% due 5/2/20064		15,000			14,940
Total short-term securities (cost: $12,800,512,000)					12,800,749
Total investment securities (cost: $59,922,324,000)					81,853,608
Other assets less liabilities					65,593
Net assets				$	81,919,201

“Miscellaneous” securities include holdings in their initial period of acquisition that have not previously been publicly disclosed.

¹Security did not produce income during the last 12 months.

²The fund owns 5% or more of the outstanding voting shares of this company. See table on the next page for additional information.

³Pass-through securities backed by a pool of mortgages or other loans on which principal payments are periodically made. Therefore, the

effective maturities are shorter than the stated maturities.

⁴Purchased in a private placement transaction; resale may be limited to qualified institutional buyers; resale to the public may require

registration. The total value of all such restricted securities was $3,039,457,000, which represented 3.71% of the net assets of the fund.

ADR = American Depositary Receipts

Investments in affiliates

A company is considered to be an affiliate of the fund under the Investment Company Act of 1940 if the fund’s holdings in that company represent 5% or more of the outstanding voting shares of that company. Further details on these holdings and related transactions during the three months ended March 31, 2006, appear below.

Company	Beginning shares		Purchases		Sales		Ending shares		Dividend income (000)		Market value of affiliates at 3/31/06 (000)
Limited Brands		20,749,400		—		706,657		20,042,743	$	3,006	$	490,245

Federal income tax information	(dollars in thousands)
Gross unrealized appreciation on investment securities		$	22,675,780
Gross unrealized depreciation on investment securities			(761,128	)
Net unrealized appreciation on investment securities			21,914,652
Cost of investment securities for federal income tax purposes			59,938,956

MFGEFP-904-0506-S4551

ITEM 2 - Controls and Procedures

The Registrant’s Principal Executive Officer and Principal Financial Officer have concluded, based on their evaluation of the Registrant’s disclosure controls and procedures (as such term is defined in Rule 30a-3 under the Investment Company Act of 1940), that such controls and procedures are adequate and reasonably designed to achieve the purposes described in paragraph (c) of such rule.

There were no changes in the Registrant’s internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) that occurred during the Registrant’s last fiscal quarter that has materially affected, or is reasonably likely to materially affect, the Registrant’s internal control over financial reporting.

ITEM 3 - Exhibits

The certifications required by Rule 30a-2 of the Investment Company Act of 1940, as amended, and Section 302 of the Sarbanes-Oxley Act of 2002 are attached as exhibits 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.

THE INVESTMENT COMPANY OF AMERICA

By /s/ R. Michael Shanahan

R. Michael Shanahan, Vice Chairman and CEO

Date: May 26, 2006

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 /s/ R. Michael Shanahan

R. Michael Shanahan, Vice Chairman and CEO

Date: May 26, 2006

By /s/ Carmelo Spinella

Carmelo Spinella, Treasurer and PFO

Date: May 26, 2006