On October 16, 2009, Prosperity Bancshares, Inc. publicly disseminated a press release announcing its financial results for the third quarter ending September 30, 2009. A copy of the press release is attached as Exhibit 99.1 hereto and incorporated herein by reference.

In addition to financial results determined in accordance with generally accepted accounting principles ("GAAP"), the press release also contains financial information determined by methods other than in accordance with GAAP. Specifically, Prosperity reviews tangible book value per share, return on average tangible common equity and the tangible equity to tangible assets ratio for internal planning and forecasting purposes. Prosperity also reviewed its net income, earnings per share, non-interest expense and related performance ratios for the three and nine month periods ending September 30, 2008 excluding the non-recurring impairment charge on Fannie Mae and Freddie Mac perpetual preferred securities. Prosperity's management believes these non-GAAP financial measures, together with the accompanying reconciliations, provide information useful to investors in understanding Prosperity's financial results, provide a more complete understanding of factors and trends affecting Prosperity's business and allow investors to view performance in a manner similar to management, the entire financial services sector, bank stock analysts and bank regulators. Further, Prosperity believes that these non-GAAP measures provide useful information by excluding certain items that may not be indicative of its core operating earnings and business outlook.

As provided in General Instruction B.2 to Form 8-K, the information furnished in Item 2.02 and Exhibit 99.1 of this Current Report on Form 8-K shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liabilities of that section, and such information shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

(d) Exhibits. The following is furnished as an exhibit to this Current Report on Form 8-K:

  Exhibit
  Number  Description of Exhibit

  99.1    Press Release issued by Prosperity Bancshares, Inc. dated October 16,
          2009.