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): January 3, 2000
  
  
                                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.
  
       (a) On January 3, 2000, Greater Bay Bancorp (the "Registrant") issued a
  press release announcing the positive results of the year 2000 rollover, a copy
  of which is attached hereto as Exhibit 99.1.
  
       (b) On January 18, 2000, the Registrant issued a press release announcing
  its 1999 year end earnings, a copy of which is attached hereto as Exhibit 99.2.
  
       (c) On January 31, 2000 the Registrant consummated its merger with Mt.
  Diablo Bancshares ("MDB") pursuant to an Agreement and Plan of Reorganization,
  dated as of September 15, 1999 (the "Agreement"), providing for the merger of
  MDB with and into the Registrant (the "Merger"). In accordance with the
  Agreement, former shareholders of MDB received 0.9532 shares of the Registrant's
  common stock in exchange for each of their shares of MDB common stock. As a
  result of the Merger, Mt. Diablo National Bank, formerly a wholly owned
  subsidiary of MDB, became a wholly owned subsidiary of the Registrant. The
  Merger was accounted for as a pooling of interests.
  
       The Registrant issued a press release announcing completion of the Merger
  on February 1, 2000 a copy of which is attached hereto as Exhibit 99.3.
  
       For a more detailed discussion of the terms and conditions of the Agreement
  and the Merger, reference is made to the Registrant's Registration Statement on
  Form S-4 (Registration No. 333-90025) filed with the Securities and Exchange
  Commission on November 1, 1999, as amended by Amendment No. 1 thereto filed with
  the Securities and Exchange Commission on November 9, 1999, incorporated herein
  by this reference.
  
  Item 7.  Financial Statements and Exhibits.
  
  Exhibits
  --------
  
   2.1    Agreement and Plan of Reorganization, dated as of September 15, 1999, by
          and between Greater Bay Bancorp and Mt. Diablo Bancshares (incorporated
          by reference from the Registrant's Current Report on Form 8-K dated
          September 21, 1999)
  
  99.1    Press Release dated January 3, 2000
  
  99.2    Press Release dated January 19, 2000
  
  99.3    Press Release dated February 1, 2000
  
                                         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: February 4, 2000               By:   /s/ Linda M. Iannone
                                              --------------------
                                              Linda M. Iannone
                                              Senior Vice President and General
                                              Counsel
  
                                         3
  <PAGE>
  
                                   Exhibit Index
                                   -------------
  
   2.1    Agreement and Plan of Reorganization, dated as of September 15, 1999, by
          and between Greater Bay Bancorp and Mt. Diablo Bancshares (incorporated
          by reference from the Registrant's Current Report on Form 8-K dated
          September 21, 1999)
  
  99.1    Press Release dated January 3, 2000
  
  99.2    Press Release dated January 19, 2000
  
  99.3    Press Release dated February 1, 2000
metadata_documents: [{"type": "8-K", "sequence": "1", "description": "FORM 8-K", "secsgml_size_bytes": 4435}]
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": "523360"}, "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): January 3, 2000
  
                                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.
  
       (a) On January 3, 2000, Greater Bay Bancorp (the "Registrant") issued a
  press release announcing the positive results of the year 2000 rollover, a copy
  of which is attached hereto as Exhibit 99.1.
  
       (b) On January 18, 2000, the Registrant issued a press release announcing
  its 1999 year end earnings, a copy of which is attached hereto as Exhibit 99.2.
  
       (c) On January 31, 2000 the Registrant consummated its merger with Mt.
  Diablo Bancshares ("MDB") pursuant to an Agreement and Plan of Reorganization,
  dated as of September 15, 1999 (the "Agreement"), providing for the merger of
  MDB with and into the Registrant (the "Merger"). In accordance with the
  Agreement, former shareholders of MDB received 0.9532 shares of the Registrant's
  common stock in exchange for each of their shares of MDB common stock. As a
  result of the Merger, Mt. Diablo National Bank, formerly a wholly owned
  subsidiary of MDB, became a wholly owned subsidiary of the Registrant. The
  Merger was accounted for as a pooling of interests.
  
       The Registrant issued a press release announcing completion of the Merger
  on February 1, 2000 a copy of which is attached hereto as Exhibit 99.3.
  
       For a more detailed discussion of the terms and conditions of the Agreement
  and the Merger, reference is made to the Registrant's Registration Statement on
  Form S-4 (Registration No. 333-90025) filed with the Securities and Exchange
  Commission on November 1, 1999, as amended by Amendment No. 1 thereto filed with
  the Securities and Exchange Commission on November 9, 1999, incorporated herein
  by this reference.
  
  Item 7.  Financial Statements and Exhibits.
  
  Exhibits
  --------
  
   2.1    Agreement and Plan of Reorganization, dated as of September 15, 1999, by
          and between Greater Bay Bancorp and Mt. Diablo Bancshares (incorporated
          by reference from the Registrant's Current Report on Form 8-K dated
          September 21, 1999)
  
  99.1    Press Release dated January 3, 2000
  
  99.2    Press Release dated January 19, 2000
  
  99.3    Press Release dated February 1, 2000
  
                                         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: February 4, 2000               By:   /s/ Linda M. Iannone
                                              --------------------
                                              Linda M. Iannone
                                              Senior Vice President and General
                                              Counsel
  
                                         3
  Exhibit Index
                                   -------------
  
   2.1    Agreement and Plan of Reorganization, dated as of September 15, 1999, by
          and between Greater Bay Bancorp and Mt. Diablo Bancshares (incorporated
          by reference from the Registrant's Current Report on Form 8-K dated
          September 21, 1999)
  
  99.1    Press Release dated January 3, 2000
  
  99.2    Press Release dated January 19, 2000
  
  99.3    Press Release dated February 1, 2000