Westamerica Bank

April 17, 2007

For Immediate Release



San Rafael, CA: Westamerica Bancorporation (NASDAQ: WABC), parent company of Westamerica Bank, today reported quarterly net income for the first quarter of 2007 of $23.6 million or $0.76 diluted earnings per share compared to $26.1 million or $0.81 diluted earnings per share for the first quarter of 2006. First quarter 2007 results include a gain on company-owned life insurance which contributed $0.02 to diluted earnings per share. First quarter 2007 return on average equity was 23.0 percent compared to 24.9 percent for the first quarter 2006.

"First quarter 2007 results remain at high profitability levels. Return on assets was 2.03 percent in spite of the challenging interest rate environment, competitive pressures, and seasonal deposit flows," said Chairman, President and CEO David Payne. "Our low 1.70 percent cost of funds, non-interest income growth, stable credit quality, and operating efficiencies contributed to these results," added Payne.

Net interest income on a fully taxable equivalent (FTE) basis was $46.9 million for the first quarter of 2007, compared to $49.0 million for the prior quarter and to $54.0 million for the first quarter of 2006. The first quarter 2007 net interest margin on a fully taxable equivalent basis was 4.41 percent, compared to 4.49 percent for the prior quarter and 4.73 percent for the first quarter of 2006.

The provision for loan losses was $75 thousand for the first quarter of 2007, compared to $70 thousand for the previous quarter, and $150 thousand for the first quarter of 2006. Net loan losses totaled $516 thousand or 0.08 percent of average loans (annualized) for the first quarter of 2007.

Noninterest income for the first quarter of 2007 totaled $15.3 million compared to $13.6 million for the first quarter 2006. Of the $1.7 million increase, service charges on deposit accounts increased $445 thousand, debit card fees increased $67 thousand, merchant credit card processing fees increased $64 thousand, and $822 thousand represents a gain on company-owned life insurance.

Noninterest expense for the first quarter of 2007 totaled $24.7 million, $819 thousand lower than noninterest expense for the first quarter of 2006. The decrease is primarily due to lower personnel and equipment costs. The first quarter 2007 efficiency ratio (expenses/revenues) was 39.7 percent compared to 37.7 percent in the first quarter 2006.

At March 31, 2007, shareholders' equity was $420 million and the equity-to-asset ratio was 8.8 percent. First quarter 2007 repurchases of the Company's common stock totaled approximately 389 thousand shares, net of shares issued.

At March 31, 2007, the Company's assets totaled $4.7 billion and total loans outstanding totaled $2.5 billion.

Westamerica Bancorporation, through its wholly owned subsidiary Westamerica Bank, operates 87 branches and two trust offices throughout 21 Northern and Central California counties.

Quarterly Financial Highlights

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-K for the year ended December 31, 2006, 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, and 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.

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