Westamerica Completes Branch Sale

SAN RAFAEL, Calif.--June 13, 2005--On June 10, 2005, Westamerica Bancorporation completed the sale of one of its two branch offices located in Lakeport, California. The branch sale was required by the Board of Governors of the Federal Reserve System as a condition to approving Westamerica's acquisition of Redwood Empire Bancorp, which was completed March 1, 2005. The deposits sold in the branch transaction represented approximately one percent of Westamerica's total deposits of $3.9 billion at March 31, 2005.

Following completion of this transaction, Westamerica Bancorporation, through its wholly owned subsidiary Westamerica Bank, operates 89 branches and two trust offices throughout 22 Northern and Central California counties. At March 31, 2005, Westamerica's assets totaled approximately $5.2 billion.

Westamerica Bancorporation Web Address: www.westamerica.com

FORWARD-LOOKING INFORMATION:

The following appears in accordance with the Private Securities Litigation Reform Act of 1995:

This press release may contain forward-looking statements about the Company, including descriptions of plans or objectives of its management for future operations, products or services, and forecasts of its revenues, earnings or other measures of economic performance. Forward-looking statements can be identified by the fact that they do not relate strictly to historical or current facts. They often include the words "believe," "expect," "anticipate," "intend," "plan," "estimate," or words of similar meaning, or future or conditional verbs such as "will," "would," "should," "could," or "may."

Forward-looking statements, by their nature, are subject to risks and uncertainties. A number of factors -- many of which are beyond the Company's control -- could cause actual conditions, events or results to differ significantly from those described in the forward-looking statements. The Company's most recent annual and quarterly reports filed with the Securities and Exchange Commission, including the Company's Form 10-Q for the quarter ended March 31, 2005 and Form 10-K for the year ended December 31, 2004, describe some of these factors, including certain credit, market, operational, liquidity and interest rate risks associated with the Company's business and operations. Other factors described in these reports include changes in business and economic conditions, competition, fiscal and monetary policies, disintermediation, legislation including the Sarbanes-Oxley Act of 2002 and the Gramm-Leach-Bliley Act of 1999, the combination of the former Redwood Empire Bancorp and other mergers and acquisitions.

Forward-looking statements speak only as of the date they are made. The Company does not undertake to update forward-looking statements to reflect circumstances or events that occur after the date forward looking statements are made.