Exhibit 99.1

FIRST FINANCIAL BANKSHARES ANNOUNCES

THIRD QUARTER EARNINGS RESULTS

ABILENE, Texas, October 18, 2012 – First Financial Bankshares, Inc. (NASDAQ: FFIN) today reported earnings for the third quarter of 2012 of $19.80 million, up 9.47 percent compared with earnings of $18.09 million in the same quarter last year. Basic earnings per share were $0.63 for the third quarter of 2012 compared with $0.58 in the same quarter a year ago.

Net interest income increased 2.11 percent to $39.12 million compared with $38.31 million in 2011. The net interest margin, on a taxable equivalent basis, was 4.26 percent compared with 4.62 percent in the same quarter last year and 4.33 percent in the second quarter of this year.

The provision for loan losses was $787 thousand in the third quarter of 2012, compared with $1.35 million in the same quarter last year and $759 thousand in the second quarter of this year. Nonperforming assets as a percentage of loans and foreclosed assets totaled 1.53 percent at September 30, 2012, compared with 1.76 percent at June 30, 2012, and 1.60 percent at September 30, 2011. Classified loans totaled $76.48 million at September 30, 2012, compared to $80.86 million at June 30, 2012, and $82.99 million at September 30, 2011.

Noninterest income increased 11.42 percent in the third quarter of 2012 to $15.50 million compared with $13.91 million in the same quarter a year ago. Trust fees increased to $3.72 million in the third quarter of 2012 compared with $3.27 million in the same quarter last year, primarily due to continued growth in the fair value of Trust assets managed to $2.75 billion from $2.30 billion a year ago. ATM, interchange and credit card fees increased 6.29 percent to $3.77 million compared with $3.54 million in the same quarter last year. Service charges on deposit accounts decreased to $4.34 million during the third quarter of 2012 compared with $4.48 million for the same quarter a year ago, due primarily to decreased customer use of overdraft services. The net gain on securities sold during the third quarter of 2012 totaled $1.48 million compared to $67 thousand in the same quarter of 2011.

Noninterest expense increased in the third quarter of 2012 to $27.20 million from $26.32 million in the same quarter last year. The Company’s efficiency ratio in the third quarter of 2012 improved to 46.61 percent compared with 47.48 percent in the same quarter last year.

For the first nine months of 2012, net income increased 9.83 percent to $55.91 million from $50.90 million for the same period a year ago. Basic earnings per share rose to $1.78 in the first nine months of 2012 from $1.62 in the same period last year. Net

interest income increased 1.86 percent to $115.93 million in the first nine months of 2012 from $113.81 million a year ago. The provision for loan losses totaled $2.84 million compared with $5.41 million in the first nine months of the previous year. Noninterest income was $42.26 million in the first nine months of 2012 compared with $38.65 million for the same period a year ago. Noninterest expense rose to $80.42 million in the first nine months of 2012 compared with $78.37 million last year.

As of September 30, 2012, consolidated assets for the Company totaled $4.31 billion compared with $3.94 billion a year ago. Loans grew 15.91 percent and totaled $2.00 billion at quarter end compared with loans of $1.73 billion a year ago. Total deposits were $3.44 billion as of September 30, 2012, which represents an 8.09 percent growth over $3.19 billion a year earlier. Shareholders’ equity rose to $549.91 million as of September 30, 2012, compared with $499.20 million the prior year.

“This was another good quarter for our company,” said F. Scott Dueser, Chairman, President and CEO. “We continue to see good growth in loans and deposits and continue to pursue acquisition prospects to put our capital to use.”

Additionally, the Company announced today that it will consolidate its eleven charters into one charter, effective at the end of the 2012 fiscal year, subject to regulatory approval. “Due to regulatory, compliance and technology complexities and the opportunity for additional cost savings, we believe it is time to make this enhancement,” stated Scott Dueser. “Outside of consolidating the eleven databases, our banks will continue to operate as they do today with local management and board decisions to benefit the customers and communities we serve,” added Dueser.

About First Financial Bankshares

Headquartered in Abilene, Texas, First Financial Bankshares is a financial holding company that operates 11 separately chartered banks with 54 locations in Texas. The bank subsidiaries are First Financial Bank, N.A., Abilene, Albany, Clyde, Moran and Odessa; First Financial Bank, N.A., Eastland, Ranger, Cisco and Rising Star; First Financial Bank, N.A., Cleburne, Burleson, Alvarado, Midlothian and Crowley; First Financial Bank, Hereford; First Financial Bank, Huntsville; First Financial Bank, N.A., Mineral Wells; First Financial Bank, N.A., San Angelo; First Financial Bank, N.A., Southlake, Bridgeport, Boyd, Decatur, Grapevine, Keller and Trophy Club; First Financial Bank, N.A., Stephenville, Granbury, Glen Rose and Acton; First Financial Bank, N.A., Sweetwater, Roby, Trent and Merkel; and First Financial Bank, N.A., Weatherford, Willow Park, Aledo, Brock and Fort Worth. The Company also operates First Financial Trust & Asset Management Company, N.A., with six 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.

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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.

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FIRST FINANCIAL BANKSHARES, INC.

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