U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): September 26, 2003

BUSINESS BANCORP

(Exact name of registrant as specified in its charter)

000-31593

(Commission File Number)

California		33-0884369
(State or Other Jurisdiction of Incorporation or Organization)		(I.R.S. Employer Identification No.)

1248 Fifth Avenue
San Rafael, California 94901
(415) 784-2300

(Address and telephone number of principal executive offices)

Item 5. Other Events

On September 26, 2003, Business Bancorp issued a press release announcing the acquisition of Business Bank of California by Union Bank of California. The press release, which appears as Exhibit 99.1, is filed and incorporated herein by reference.

Item 7. Exhibits

(c) Exhibits

99.1 Press Release dated September 26, 2003 re: acquisition of Business Bank of California by Union Bank of California.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized, on the 26th day of September, 2003.

	By /s/ Patrick E. Phelan
	Patrick E. Phelan
	Executive Vice President / Chief Financial Officer
	(Principal Financial Officer)
	(Principal Accounting Officer)
	Director

BUSINESS BANCORP /CA/ 8-K