content: <PAGE>
  
                        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): December 22, 1999
  
  
                                Greater Bay Bancorp
              (Exact name of registrant as specified in its charter)
  
  
  
          California                                   77-0387041
  (State or other jurisdiction of                     (I.R.S. employer
  incorporation or organization)                      identification number)
  
  
                         Commission file number:  0-25034
  
  
                              2860 West Bayshore Road
                            Palo Alto, California 94303
               (Address of principal executive offices and zip code)
  
  
        Registrant's telephone number, including area code: (650) 813-8200
  <PAGE>
  
  Item 5.  Other Events.
  
        On December 22, 1999 the ("Closing Date"), Greater Bay Bancorp (the
  "Registrant") consummated the sale of 535,000 shares (the "Shares") of the
  Registrant's common stock, no par value, in a private offering pursuant to a
  Securities Purchase Agreement, dated as of December 21, 1999, between the
  Registrant and certain investors identified therein (the "Investors"). The
  Registrant sold the Shares for a purchase price of $37.00 per share, or an
  aggregate amount of $19,795,000. In addition, the Registrant entered into a
  Registration Rights Agreement with the Investors pursuant to which the
  Registrant has agreed to file, within thirty (30) business days of the Closing
  Date, a registration statement with the Securities and Exchange Commission
  registering the Shares under the Securities Act of 1933, as amended.
  
  Item 7.  Financial Statements and Exhibits.
  
  Exhibits
  --------
  
   4.1  Securities Purchase Agreement, dated as of December 21, 1999, between the
        Registrant and the Investors
  
   4.2  Registration Rights Agreement, dated as of December 22, 1999, between the
        Registrant and the Investors
  
   99.1 Press Release dated December 22, 1999 re completion of the offering
  
                                         2
  <PAGE>
  
                                    SIGNATURES
  
            Pursuant to the requirements of the Securities Exchange Act of 1934,
       as amended, the Registrant has duly caused this report to be signed on its
       behalf by the undersigned hereunto duly authorized.
  
                                     Greater Bay Bancorp
                                     (Registrant)
  
  
  
  Dated: December 27, 1999           By: /s/ Linda M. Iannone
                                         --------------------
                                         Linda M. Iannone
                                         Senior Vice President and General Counsel
  
                                         3
  <PAGE>
  
                                   Exhibit Index
                                   -------------
   4.1 Securities Purchase Agreement, dated as of December 21, 1999, between the
       Registrant and the Investors
  
   4.2 Registration Rights Agreement, dated as of December 22, 1999, between the
       Registrant and the Investors
  
  99.1 Press Release dated December 22, 1999 regarding completion of the offering
  
                                         4
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metadata_filer: {"company-data": {"conformed-name": "GREATER BAY BANCORP", "cik": "0000775473", "assigned-sic": "6021", "irs-number": "770387041", "state-of-incorporation": "CA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "000-25034", "film-number": "99781498"}, "business-address": {"street1": "2860 WEST BAYSHORE ROAD", "city": "PALO ALTO", "state": "CA", "zip": "94303", "phone": "4153751555"}, "mail-address": {"street1": "2860 BAYSHORE ROAD", "street2": "420 COWPER ST", "city": "PALO ALTO", "state": "CA", "zip": "943011504"}, "former-company": [{"former-conformed-name": "MID PENINSULA BANCORP", "date-changed": "19941031"}, {"former-conformed-name": "SAN MATEO COUNTY BANCORP", "date-changed": "19920703"}]}
text: 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): December 22, 1999
  
                                Greater Bay Bancorp
              (Exact name of registrant as specified in its charter)
  
          California                                   77-0387041
  (State or other jurisdiction of                     (I.R.S. employer
  incorporation or organization)                      identification number)
  
                         Commission file number:  0-25034
  
                              2860 West Bayshore Road
                            Palo Alto, California 94303
               (Address of principal executive offices and zip code)
  
        Registrant's telephone number, including area code: (650) 813-8200
  Item 5.  Other Events.
  
        On December 22, 1999 the ("Closing Date"), Greater Bay Bancorp (the
  "Registrant") consummated the sale of 535,000 shares (the "Shares") of the
  Registrant's common stock, no par value, in a private offering pursuant to a
  Securities Purchase Agreement, dated as of December 21, 1999, between the
  Registrant and certain investors identified therein (the "Investors"). The
  Registrant sold the Shares for a purchase price of $37.00 per share, or an
  aggregate amount of $19,795,000. In addition, the Registrant entered into a
  Registration Rights Agreement with the Investors pursuant to which the
  Registrant has agreed to file, within thirty (30) business days of the Closing
  Date, a registration statement with the Securities and Exchange Commission
  registering the Shares under the Securities Act of 1933, as amended.
  
  Item 7.  Financial Statements and Exhibits.
  
  Exhibits
  --------
  
   4.1  Securities Purchase Agreement, dated as of December 21, 1999, between the
        Registrant and the Investors
  
   4.2  Registration Rights Agreement, dated as of December 22, 1999, between the
        Registrant and the Investors
  
   99.1 Press Release dated December 22, 1999 re completion of the offering
  
                                         2
  SIGNATURES
  
            Pursuant to the requirements of the Securities Exchange Act of 1934,
       as amended, the Registrant has duly caused this report to be signed on its
       behalf by the undersigned hereunto duly authorized.
  
                                     Greater Bay Bancorp
                                     (Registrant)
  
  Dated: December 27, 1999           By: /s/ Linda M. Iannone
                                         --------------------
                                         Linda M. Iannone
                                         Senior Vice President and General Counsel
  
                                         3
  Exhibit Index
                                   -------------
   4.1 Securities Purchase Agreement, dated as of December 21, 1999, between the
       Registrant and the Investors
  
   4.2 Registration Rights Agreement, dated as of December 22, 1999, between the
       Registrant and the Investors
  
  99.1 Press Release dated December 22, 1999 regarding completion of the offering
  
                                         4