EXHIBIT 99.1

                              [LOGO APPEARS HERE]

PRESS RELEASE                               For more information contact:

Prosperity Bancshares, Inc.(SM)             Dan Rollins
4295 San Felipe                             Senior Vice President
Houston, Texas 77027                        713.693.9300
                                            danrollins@prosperitybanktx.com

FOR IMMEDIATE RELEASE

                     PROSPERITY BANCSHARES, INC.(SM)
                                   TO ACQUIRE
                         FIRST NATIONAL BANK OF BAY CITY

            Prosperity Bank(SM) expands presence in Matagorda County

HOUSTON, August 15, 2002. Prosperity Bancshares, Inc.(SM) (NASDAQ: PRSP), the
parent company of Prosperity Bank(SM), announced today the signing of a
definitive agreement to acquire First National Bank of Bay City in a cash
transaction valued at $5.0 million and subject to certain adjustments. The
acquisition is expected to close in the fourth quarter 2002. The proposed
transaction is subject to certain conditions and approval by regulators.

First National Bank of Bay City operates one (1) office in Bay City, Texas,
which will be consolidated (upon completion of the transaction) with Prosperity
Bank's(SM) full service banking center in Bay City. On June 30, 2002, First
National Bank of Bay City reported total assets of $26.9 million, total deposits
of $23.2 million and total loans of $9.1 million.

"We have been looking for opportunities to expand our presence in Matagorda
County for the past few years and believe that the addition of First National
Bank of Bay City's customers and experienced staff is a perfect fit," said David
Zalman, Chief Executive Officer and President of Prosperity Bancshares, Inc. "We
are pleased that First National Bank of Bay City chose to become our partner in
providing what we believe to be the highest level of customer focused banking
services in the markets we serve."

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"The decision to sell our bank after operating as an independent bank and
providing quality banking services to our customers was not easy," said Jack I.
Conner President and Chief Executive Officer of First National Bank of Bay City.
"However, we are convinced that joining Prosperity Bank(SM) is the right choice
for our customers. We all look forward to becoming a member of the Prosperity
team and continuing our personal involvement with the customers of our bank."

"Our new customers will continue to enjoy the same type of people to people
banking they have enjoyed with First National Bank of Bay City," said Dan
Rollins, Matagorda County Banking Centers President of Prosperity Bank(SM). "We
are committed to providing our entire customer base with quality banking
products and services now and in the future. Upon the completion of this
acquisition, Prosperity Bank(SM) will become the largest bank in Matagorda
County in both loans and deposits."

Upon consummation of the acquisition, Jack I. Conner will assume management
responsibility for Prosperity Bank's(SM) full service banking centers in Bay
City and Palacios and will become Matagorda County Banking Centers President.

Prosperity Bancshares, Inc.(SM), formed in 1983, is a $1.360 billion bank
holding company headquartered in Houston, Texas. Operating under a community
banking philosophy, Prosperity seeks to develop broad customer relationships
based on service and convenience. Prosperity offers a variety of traditional
loan and deposit products to its customers, which consist primarily of consumers
and small and medium sized businesses. In addition to established banking
products, Prosperity offers a complete line of services including: Internet
Banking services at www.prosperitybanktx.com, Trust and Investment Services,
MasterMoney Debit Cards, and 24 hour voice response banking. The bank currently
operates thirty-two (32) full service banking locations in fourteen (14)
contiguous counties including the Greater Houston Metropolitan Area. (Angleton,
Bay City, Beeville, Clear Lake, Cleveland, Cuero, Cypress, East Bernard, Edna,
El Campo, Fairfield, Goliad, Hitchcock, Houston -Bellaire, Houston - CityWest,
Houston - Downtown, Houston - Highway 6, Houston - Medical Center, Houston -
Memorial,

Houston - Post Oak, Houston - River Oaks, Houston - Tanglewood, Houston -Waugh
Drive, Liberty, Magnolia, Mathis, Needville, Palacios, Sweeny, Victoria, West
Columbia, and Wharton.)

"Safe Harbor" Statement under the Private Securities Litigation Reform Act of
1995: The statements contained in this release which are not historical facts
contain forward-looking information with respect to plans, projections or future
performance of Prosperity Bancshares, Inc.(SM) and its subsidiaries.
Forward-looking statements, within the meaning of Section 21E of the Securities
Exchange Act of 1934, may have been made in this document. Prosperity's results
may differ materially from those in the forward-looking statements for a variety
of reasons, including actions of competitors; changes in laws and regulations
(including changes in governmental interpretations of regulations and changes in
accounting standards); customer and consumer demand, including customer and
consumer response to marketing; effectiveness of spending, investments or
programs; fluctuations in the cost and availability of supply chain resources;
economic conditions, including currency rate fluctuations; and weather. These
factors are more fully described in Prosperity Bancshares, Inc.'s filings with
the Securities and Exchange Commission.

Copies of Prosperity Bancshares, Inc.'s(SM) SEC filings may be downloaded from
the Internet at no charge from FreeEDGAR, a real-time access to SEC filings site
located at www.freeedgar.com.

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