EXHIBIT 5.1 OPINION RE: LEGALITY -7- NIXON PEABODY LLP Two Embarcadero Center Suite 2700 San Francisco, CA 94111-3996 (415) 984-8200 Fax: (415) 984-8300 R. Brent Faye Direct Dial: (415) 984-8365 E-Mail: rfaye@nixonpeabody.com June 4, 2002 North Bay Bancorp 1500 Soscol Avenue Napa , CA, 94558 Ladies and Gentlemen: With reference to the Registration Statement on Form S-8 filed by North Bay Bancorp ("North Bay") with the Securities and Exchange Commission in connection with the registration under the Securities Act of 1933, as amended, of 587,229 shares of North Bay Common Stock no par value, (the "Shares") to be issued in connection with the grant and exercise of options and resale of shares under the North Bay Bancorp 2002 Stock Option Plan (the "Stock Option Plan"): We are of the opinion that the Shares have been duly authorized and, when issued in accordance with the Stock Option Plan, will be validly issued, fully paid and nonassessable. We hereby consent to the filing of this opinion as Exhibit 5.1 to the Registration Statement, and any amendments thereto, and the use of our name under the caption "Legal Matters" in the Registration Statement, and any amendments thereto, and in the Prospectus included therein. Very truly yours, \S\ NIXON PEABODY LLP -8-