Exhibit 99.1

For immediate release For More Information: J. Bruce Hildebrand, Executive Vice President       325.627.7155

FIRST FINANCIAL BANKSHARES ANNOUNCES FIRST QUARTER EARNINGS RESULTS

ABILENE, Texas, April 19, 2018 – The Board of Directors of – First Financial Bankshares, Inc. (NASDAQ: FFIN) today reported earnings for the first quarter of 2018 of $34.52 million, up $7.92 million when compared with earnings of $26.60 million in the same quarter last year. Basic earnings per share were $0.51 for the first quarter of 2018 compared with $0.40 in the same quarter a year ago. The increase in net earnings and earnings per share in the current quarter when compared with the same quarter a year ago largely resulted from the recent enactment of tax legislation that reduced the corporate income tax rate from 35 percent to 21 percent. Without this adjustment, net earnings for the first quarter of 2018 would have been $30.26 million with an adjusted basic earnings per share of $0.45.

All amounts for the first quarter ended March 31, 2018, include the results of the Company’s recent acquisition of Commercial Bancshares, Inc. and its wholly-owned subsidiary, Commercial State Bank, Kingwood, Texas, which was effective January 1, 2018. As of the acquisition date, Commercial State Bank had total assets of approximately $390.20 million, total loans of approximately $271.50 million and total deposits of approximately $345.90 million.

Net interest income for the first quarter of 2018 was $65.45 million compared with $57.02 million in the same quarter of 2017. The net interest margin, on a taxable equivalent basis, was 3.88 percent for the first quarter of 2018 compared to 4.00 percent in the fourth quarter of 2017 and 4.03 percent in the first quarter of 2017. The decrease in the Company’s tax equivalent net interest margin in the current quarter when compared with the fourth quarter of 2017 and the first quarter of 2017 resulted from the change in corporate tax rate from 35 percent to 21 percent and the corresponding effect of that change on the Company’s tax exempt bond portfolio. Included in interest income for the first quarter of 2018 was $645 thousand, or four basis points in net interest margin, related to discount accretion from fair value accounting related to the Kingwood and Orange acquisitions.

The provision for loan losses was $1.31 million in the first quarter of 2018 compared with $1.44 million in the fourth quarter of 2017 and $1.95 million in the first quarter of 2017. Nonperforming assets as a percentage of loans and foreclosed assets totaled 0.66 percent at March 31, 2018, compared with 0.57 percent at December 31, 2017, and 0.90 percent at March 31, 2017. Classified loans totaled $124.06 million at March 31, 2018, compared to $117.21 million at December 31, 2017, and $122.62 million at March 31, 2017.

Noninterest income increased 14.74 percent in the first quarter of 2018 to $24.42 million compared with $21.29 million in the same quarter a year ago. Trust fees increased $887 thousand to $6.90 million in the first quarter of 2018 compared with $6.02 million in the same quarter last year, primarily due to continued growth in the fair value of Trust assets managed to $5.23 billion from $4.54 billion a year ago. ATM, interchange and credit card fees increased 13.50 percent to $7.00 million compared with $6.16 million in the same quarter last year due to continued growth in debit cards. Service charges on deposits increased 7.34 percent to $4.88 million compared with $4.55 million in the same quarter a year ago due to continued growth in net new accounts. In addition, a gain on sale of securities totaling $1.22 million was recorded in the first quarter of 2018 compared to $3 thousand in the same quarter of 2017. Offsetting these increases was a decrease in real estate mortgage fees of $484 thousand or 14.16 percent compared to the same quarter a year ago, partially due to a slowdown in refinance activity and the sale of the mortgage servicing portfolio in July 2017.

Noninterest expense for the first quarter of 2018 totaled $47.80 million compared to $42.15 million in the first quarter of 2017. The Company’s efficiency ratio in the first quarter of 2018 was 51.76 percent compared with 49.67 percent in the same quarter last year. The increase in noninterest expense in the first quarter of 2018 was primarily a result of an increase in salary and employee benefit costs to $26.20 million compared to $23.26 million in the same quarter a year ago, primarily driven by the acquisition of Commercial State Bank and annual merit based pay increases. Also included in noninterest expense in the first quarter of 2018 were technology contract termination and conversion related costs totaling $1.55 million related to the Commercial State Bank acquisition.

As of March 31, 2018, consolidated assets for the Company totaled $7.57 billion compared to $7.25 billion at December 31, 2017 and $6.93 billion at March 31, 2017. Loans totaled $3.75 billion at quarter end compared with loans of $3.50 billion at December 31, 2017, and $3.39 billion at March 31, 2017. Deposits totaled $6.19 billion at March 31, 2018, compared to $5.96 billion at December 31, 2017, and $5.66 billion at March 31, 2017. Shareholders’ equity rose to $969.81 million as of March 31, 2018, compared with $922.77 million at December 31, 2017, and $859.35 million at March 31, 2017.

“We are pleased to get off to a good start for 2018 with our first quarter earnings performance, especially in light of the additional expenses incurred to complete our acquisition of Commercial State Bank,” said F. Scott Dueser, Chairman, President and CEO. “We continue to see strong growth in trust fees and expect our recent acquisition of Commercial State Bank to contribute nicely to our bottom line. Also, we continue to visit with other potential acquisition candidates as well as working diligently on organically growing loans and deposits while reducing expenses to reward our shareholders, customers and employees even more.”

About First Financial Bankshares

Headquartered in Abilene, Texas, First Financial is a financial holding company that through its subsidiary, First Financial Bank, N.A., operates multiple banking regions with 72 locations in Texas, following the close of this acquisition, including Abilene, Acton, Albany, Aledo, Alvarado, Beaumont, Boyd, Bridgeport, Brock, Burleson, Cisco, Cleburne, Clyde, Conroe, Cut and Shoot, Decatur, Eastland, El Campo, Fort Worth, Fulshear, Glen Rose, Granbury, Grapevine, Hereford, Huntsville, Keller, Kingwood, Magnolia, Mauriceville, Merkel, Midlothian, Mineral Wells, Montgomery, Moran, New Waverly, Newton, Odessa, Orange, Palacios, Port Arthur, Ranger, Rising Star, Roby, San Angelo, Southlake, Stephenville, Sweetwater, Tomball, Trent, Trophy Club, Vidor, Waxahachie, Weatherford, Willis, and Willow Park. The Company also operates First Financial Trust & Asset Management Company, N.A., with seven locations and First Technology Services, Inc., a technology operating company.

The Company is listed on The NASDAQ Global Select Market under the trading symbol FFIN. For more information about First Financial Bankshares, please visit our website at http://www.ffin.com.

*****

Certain statements contained herein may be considered “forward-looking statements” as defined in the Private Securities Litigation Reform Act of 1995. These statements are based upon the belief of the Company’s management, as well as assumptions made beyond information currently available to the Company’s management, and may be, but not necessarily are, identified by such words as “expect”, “plan”, “anticipate”, “target”, “forecast” and “goal”. Because such “forward-looking statements” are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Factors that could cause actual results to differ materially from the Company’s expectations include competition from other financial institutions and financial holding companies; the effects of and changes in trade, monetary and fiscal policies and laws, including interest rate policies of the Federal Reserve Board; changes in the demand for loans; fluctuations in value of collateral and loan reserves; inflation, interest rate, market and monetary fluctuations; changes in consumer spending, borrowing and savings habits; and acquisitions and integration of acquired businesses, and similar variables. Other key risks are described in the Company’s reports filed with the Securities and Exchange Commission, which may be obtained under “Investor Relations-Documents/Filings” on the Company’s Web site or by writing or calling the Company at 325.627.7155. Except as otherwise stated in this news announcement, the Company does not undertake any obligation to update publicly or revise any forward-looking statements because of new information, future events or otherwise.

FIRST FINANCIAL BANKSHARES, INC.

CONSOLIDATED FINANCIAL SUMMARY (UNAUDITED)

(In thousands, except share and per share data)

	As of
	2018			2017
ASSETS	Mar. 31,			Dec 31,			Sept. 30,			June 30,			Mar. 31,
Cash and due from banks	$	130,979		$	209,583		$	177,615		$	163,435		$	163,674
Interest-bearing deposits in banks		67,060			162,764			166,820			53,336			55,165
Interest-bearing time deposits in banks		1,458			1,458			1,458			1,458			1,707
Fed funds sold		—			—			—			3,740			3,840
Investment securities		3,276,193			3,087,473			2,885,483			2,964,618			3,018,393
Loans		3,747,081			3,500,699			3,491,346			3,457,679			3,386,141
Allowance for loan losses		(49,499	)		(48,156	)		(47,922	)		(47,410	)		(46,192	)
Net loans		3,697,582			3,452,543			3,443,424			3,410,269			3,339,949
Premises and equipment		126,446			124,026			125,668			123,620			122,787
Goodwill		171,565			139,971			139,971			139,971			139,971
Other intangible assets		4,004			1,172			1,384			3,149			3,464
Other assets		92,162			75,725			67,341			83,796			81,420
Total assets	$	7,567,449		$	7,254,715		$	7,009,164		$	6,947,392		$	6,930,370
LIABILITIES AND SHAREHOLDERS’ EQUITY
Noninterest-bearing deposits	$	2,111,116		$	2,041,650		$	1,949,174		$	1,856,439		$	1,827,609
Interest-bearing deposits		4,079,647			3,921,311			3,748,286			3,770,170			3,834,359
Total deposits		6,190,763			5,962,961			5,697,460			5,626,609			5,661,968
Borrowings		372,155			331,000			351,435			379,324			360,264
Other liabilities		34,717			37,986			53,713			54,017			48,784
Shareholders’ equity		969,814			922,768			906,556			887,442			859,354
Total liabilities and shareholders’ equity	$	7,567,449		$	7,254,715		$	7,009,164		$	6,947,392		$	6,930,370
	Quarter Ended
	2018			2017
INCOME STATEMENTS	Mar. 31,			Dec 31,			Sept. 30,			June 30,			Mar. 31,
Interest income	$	69,082		$	63,456		$	62,554		$	61,182		$	58,783
Interest expense		3,633			2,562			2,866			2,097			1,763
Net interest income		65,449			60,894			59,688			59,085			57,020
Provision for loan losses		1,310			1,440			1,415			1,725			1,950
Net interest income after provision for loan losses		64,139			59,454			58,273			57,360			55,070
Noninterest income		24,423			22,302			24,260			23,170			21,286
Noninterest expense		47,798			44,096			43,964			43,775			42,152
Net income before income taxes		40,764			37,660			38,569			36,755			34,204
Income tax expense		6,245			9,167			9,195			8,500			7,605
Tax benefit from tax rate change		—			(7,650	)		—			—			—
Net income	$	34,519		$	36,143		$	29,374		$	28,255		$	26,599
PER COMMON SHARE DATA
Net income – basic	$	0.51		$	0.55		$	0.44		$	0.43		$	0.40
Net income – diluted		0.51			0.54			0.44			0.43			0.40
Cash dividends declared		0.19			0.19			0.19			0.19			0.18
Book Value		14.34			13.93			13.69			13.41			12.99
Market Value	$	46.30		$	45.05		$	45.20		$	44.20		$	40.10
Shares outstanding – end of period		67,612,760			66,260,444			66,223,957			66,170,312			66,131,832
Average outstanding shares – basic		67,527,010			66,191,995			66,140,518			66,100,089			66,073,399
Average outstanding shares – diluted		67,799,545			66,428,871			66,417,281			66,344,943			66,363,222
PERFORMANCE RATIOS
Return on average assets		1.84	%		2.02	%		1.65	%		1.64	%		1.57	%
Return on average equity		14.74			15.79			12.95			12.94			12.74
Return on average tangible equity		17.82			18.70			15.38			15.48			15.34
Net interest margin (tax equivalent)		3.88			4.00			3.94			4.05			4.03
Efficiency ratio		51.76			49.37			48.71			49.32			49.67

FIRST FINANCIAL BANKSHARES, INC.

SELECTED FINANCIAL DATA (UNAUDITED)

(In thousands)

	Quarter Ended
	2018			2017
ALLOWANCE FOR LOAN LOSSES	Mar. 31,			Dec 31,			Sept. 30,			June 30,			Mar. 31,
Balance at beginning of period	$	48,156		$	47,922		$	47,410		$	46,192		$	45,779
Loans charged off		(471	)		(1,440	)		(1,180	)		(1,174	)		(2,026	)
Loan recoveries		504			234			277			667			489
Net recoveries (charge-offs)		33			(1,206	)		(903	)		(507	)		(1,537	)
Provision for loan losses		1,310			1,440			1,415			1,725			1,950
Balance at end of period	$	49,499		$	48,156		$	47,922		$	47,410		$	46,192
Allowance for loan losses / period-end loans		1.32	%		1.38	%		1.37	%		1.37	%		1.36	%
Allowance for loan losses / nonperforming loans		209.80			259.11			243.57			210.95			159.48
Net charge-offs / average loans (annualized)		—			0.14			0.10			0.06			0.18
SUMMARY OF LOAN CLASSIFICATION
Special Mention	$	40,079		$	37,079		$	35,237		$	27,999		$	23,341
Substandard		83,976			80,131			86,057			89,609			99,280
Doubtful		—			—			—			—			—
Total classified loans	$	124,055		$	117,210		$	121,294		$	117,608		$	122,621
NONPERFORMING ASSETS
Nonaccrual loans	$	22,752		$	17,670		$	18,750		$	21,489		$	28,080
Accruing troubled debt restructured loans		514			627			668			672			695
Accruing loans 90 days past due		327			288			257			314			190
Total nonperforming loans		23,593			18,585			19,675			22,475			28,965
Foreclosed assets		1,276			1,532			2,401			2,245			1,553
Total nonperforming assets	$	24,869		$	20,117		$	22,076		$	24,720		$	30,518
As a % of loans and foreclosed assets		0.66	%		0.57	%		0.63	%		0.71	%		0.90	%
As a % of end of period total assets		0.33			0.28			0.31			0.36			0.44
OIL AND GAS PORTFOLIO INFORMATION
Oil and gas loans	$	86,218		$	60,164		$	69,433		$	70,187		$	75,262
Oil and gas loans as a % of total loans		2.30	%		1.72	%		1.99	%		2.03	%		2.22	%
Classified oil and gas loans		10,485			20,346			21,817			24,404			29,077
Nonaccrual oil and gas loans		1,460			1,414			1,569			2,860			3,208
Net charge-offs for oil and gas loans		—			—			—			50			—
Allowance for oil and gas loans as a % of oil and gas loans		3.64	%		7.90	%		6.03	%		7.24	%		6.59	%
CAPITAL RATIOS
Common equity Tier 1 capital ratio		18.62	%		18.66	%		18.35	%		17.79	%		17.56	%
Tier 1 capital ratio		18.62			18.66			18.35			17.79			17.56
Total capital ratio		19.76			19.85			19.54			18.97			18.72
Tier 1 leverage		10.98			11.09			10.84			10.79			10.60
Equity to assets		12.82			12.72			12.93			12.77			12.40

	Quarter Ended
	2018			2017
NONINTEREST INCOME	Mar. 31,			Dec 31,			Sept. 30,			June 30,			Mar. 31,
Trust fees	$	6,904		$	5,891		$	6,040		$	5,747		$	6,017
Service charges on deposits		4,884			4,900			5,083			4,883			4,550
ATM, interchange and credit card fees		6,996			6,584			6,340			6,598			6,164
Real estate mortgage fees		2,933			3,613			3,891			4,188			3,417
Net gain on sale of available-for-sale securities		1,221			3			1,075			747			3
Net gain (loss) on sale of foreclosed assets		99			(8	)		(11	)		(72	)		41
Net gain (loss) on sale of assets		(91	)		(185	)		(15	)		(200	)		4
Interest on loan recoveries		119			232			405			337			154
Other noninterest income		1,358			1,272			1,452			942			936
Total noninterest income	$	24,423		$	22,302		$	24,260		$	23,170		$	21,286
NONINTEREST EXPENSE
Salaries and employee benefits, excluding profit sharing	$	24,994		$	22,760		$	23,052		$	22,508		$	22,233
Profit sharing expense		1,209			1,661			1,091			957			1,026
Net occupancy expense		2,883			2,439			2,711			2,771			2,600
Equipment expense		3,516			3,369			3,294			3,665			3,437
FDIC insurance premiums		566			560			561			550			547
ATM, interchange and credit card expenses		2,143			1,935			2,001			1,803			1,713
Legal, tax and professional fees		2,807			2,580			2,396			2,526			2,478
Audit fees		411			338			356			379			419
Printing, stationery and supplies		486			567			449			536			438
Amortization of intangible assets		387			136			143			165			168
Advertising and public relations		1,575			1,689			1,527			1,576			1,544
Operational and other losses		566			553			1,081			574			985
Software amortization and expense		524			1,056			742			995			500
Other noninterest expense		5,731			4,453			4,560			4,770			4,064
Total noninterest expense	$	47,798		$	44,096		$	43,964		$	43,775		$	42,152
TAX EQUIVALENT YIELD ADJUSTMENT	$	2,467		$	6,125		$	6,312		$	6,509		$	6,550

FIRST FINANCIAL BANKSHARES, INC.

SELECTED FINANCIAL DATA (UNAUDITED)

(In thousands)

	Three Months Ended Mar. 31, 2018							Three Months Ended Dec. 31, 2017
	Average Balance		Tax Equivalent Interest		Yield / Rate			Average Balance		Tax Equivalent Interest		Yield / Rate
Interest-earning assets:
Fed funds sold	$	6,215	$	27		1.78	%	$	1,192	$	5		1.52	%
Interest-bearing deposits in nonaffiliated banks		160,399		613		1.55			186,355		645		1.37
Taxable securities		1,826,391		11,354		2.49			1,562,744		8,977		2.30
Tax exempt securities		1,352,235		12,559		3.72			1,405,327		16,259		4.63
Loans		3,748,561		46,995		5.08			3,483,939		43,695		4.98
Total interest-earning assets		7,093,801	$	71,548		4.09	%		6,639,557	$	69,581		4.16	%
Noninterest-earning assets		497,049							441,645
Total assets	$	7,590,850						$	7,081,202
Interest-bearing liabilities:
Deposits	$	4,139,324	$	3,519		0.34	%	$	3,795,808	$	2,465		0.26	%
Fed funds purchased and other borrowings		357,414		113		0.13			343,683		97		0.11
Total interest-bearing liabilities		4,496,738	$	3,632		0.33	%		4,139,491	$	2,562		0.25	%
Noninterest-bearing liabilities		2,144,065							2,033,580
Shareholders’ equity		950,047							908,131
Total liabilities and shareholders’ equity	$	7,590,850						$	7,081,202
Net interest income and margin (tax equivalent)			$	67,916		3.88	%			$	67,019		4.00	%
	Three Months Ended Sept. 30, 2017							Three Months Ended June 30, 2017
	Average Balance		Tax Equivalent Interest		Yield / Rate			Average Balance		Tax Equivalent Interest		Yield / Rate
Interest-earning assets:
Fed funds sold	$	2,467	$	9		1.43	%	$	5,229	$	8		0.64	%
Interest-bearing deposits in nonaffiliated banks		198,322		629		1.26			45,043		112		1.00
Taxable securities		1,492,246		8,074		2.16			1,494,187		8,343		2.23
Tax exempt securities		1,477,559		16,884		4.57			1,528,760		17,414		4.56
Loans		3,468,524		43,270		4.95			3,418,105		41,814		4.91
Total interest-earning assets		6,639,118	$	68,866		4.12	%		6,491,324	$	67,691		4.18	%
Noninterest-earning assets		431,070							428,245
Total assets	$	7,070,188						$	6,919,569
Interest-bearing liabilities:
Deposits	$	3,728,442	$	2,228		0.24	%	$	3,803,412	$	1,930		0.20	%
Fed funds purchased and other borrowings		524,357		638		0.48			372,910		167		0.18
Total interest-bearing liabilities		4,252,799	$	2,866		0.27	%		4,176,322	$	2,097		0.20	%
Noninterest-bearing liabilities		1,917,681							1,867,596
Shareholders’ equity		899,708							875,651
Total liabilities and shareholders’ equity	$	7,070,188						$	6,919,569
Net interest income and margin (tax equivalent)			$	66,000		3.94	%			$	65,594		4.05	%

	Three Months Ended Mar. 31, 2017
	Average Balance		Tax Equivalent Interest		Yield / Rate
Interest-earning assets:
Fed funds sold	$	3,529	$	2		0.23	%
Interest-bearing deposits in nonaffiliated banks		134,556		274		0.83
Taxable securities		1,367,331		7,431		2.17
Tax exempt securities		1,529,610		17,561		4.59
Loans		3,369,599		40,065		4.82
Total interest-earning assets		6,404,625	$	65,333		4.14	%
Noninterest-earning assets		446,961
Total assets	$	6,851,586
Interest-bearing liabilities:
Deposits	$	3,808,933	$	1,590		0.17	%
Fed funds purchased and other borrowings		448,217		173		0.16
Total interest-bearing liabilities		4,257,150	$	1,763		0.17	%
Noninterest-bearing liabilities		1,747,532
Shareholders’ equity		846,904
Total liabilities and shareholders’ equity	$	6,851,586
Net interest income and margin (tax equivalent)			$	63,570		4.03	%