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EXHIBIT 5           OPINION OF MULDOON, MURPHY & FAUCETTE



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                                                   June 26, 1996


Board of Directors
Monterey Bay Bancorp, Inc.
36 Brennan Street
Watsonville, California 95076

         Re:      Monterey Bay Bancorp, Inc. 1995 Incentive Stock Option Plan -
                  Monterey Bay Bancorp, Inc. 1995 Stock Option Plan for
                  Outside Directors
                  Registration Statement on Form S-8 for 359,750 Shares of
                  Common Stock

Gentlemen:

     We have acted as counsel for Monterey Bay Bancorp,  Inc. (the "Company") in
connection with the  registration  under the Securities Act of 1933, as amended,
on Form S-8 of  359,750  of the  Company's  Common  Stock,  $.01 par value  (the
"Shares"),  to be issued under the Monterey Bay  Bancorp,  Inc.  1995  Incentive
Stock Option Plan and the Monterey Bay Bancorp,  Inc. 1995 Stock Option Plan for
Outside Directors (the "Plans").

     As such  counsel,  we have made such  legal and  factual  examinations  and
inquiries as we deemed  advisable for the purpose of rendering this opinion.  In
our  examination,  we have assumed and have not verified (i) the  genuineness of
all  signatures,  (ii) the  authenticity  of all  documents  submitted  to us as
originals,  (iii) the conformity with the originals of all documents supplied to
us as copies,  and (iv) the accuracy and  completeness of all corporate  records
and documents and of all certificates and statements of fact, in each case given
or made available to us by the Company or its subsidiary.

     Based on the  foregoing and limited in all respects to Delaware law and the
facts as they  exist on the  date  hereof,  it is our  opinion  that the  Shares
reserved under the Plans have been duly  authorized and upon the issuance of the
Shares in the manner described in the Plans, will be legally issued,  fully paid
and  nonassessable.  The following  provisions of the Company's  Certificate  of
Incorporation  may not be given effect by a court applying  Delaware law, but in
our opinion the  failure to give effect to such  provisions  will not affect the
duly  authorized,  validly issued,  fully paid and  nonassessable  status of the
Shares:


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        (1)    (a)  Subsections  C.3 and C.6 of Article  FOURTH and Section D of
               Article EIGHTH, which grant the Board of Directors of the Company
               ("Board") the  authority to construe and apply the  provisions of
               those Articles,  Subsection C.4 of Article  FOURTH,  which grants
               authority to the Board to determine  whether a  stockholder  owns
               shares in excess of the Limit,  and the  provision of  Subsection
               C.7 of Article EIGHTH  empowering the Board to determine the Fair
               Market Value of property  offered or paid for the Company's stock
               by an Interested Stockholder, to the extent, if any, that a court
               applying  Delaware law were to impose equitable  limitations upon
               the  authority  of  the  directors  of  the  Company  under  such
               provisions; and

               (b) Article  NINTH of the  Certificate  of  Incorporation,  which
               authorizes  the  Board to  consider  the  effect  of any offer to
               acquire the Company on constituencies  other than stockholders in
               evaluating any such offer.

        This  opinion  is based upon the facts and law as they exist on the date
hereof.  We assume no  obligation  to update  this  opinion or advise you of any
events that occur subsequent to the date of this opinion.  This opinion is being
furnished to you solely in response to the requirement  contained in Item 601 of
Regulation  S-K for your  benefit and may not be relied upon by any other person
or for any other  purpose,  and it  should  not be quoted in whole or in part or
otherwise  referred to or furnished  to any other  person or entity  without the
prior  written  consent  of this firm.  We hereby  consent to the filing of this
opinion as an exhibit to the  Company's  Registration  Statement on Form S-8. We
note  that,  although  certain  portions  of  the  Registration  Statement  (the
financial  statements and schedules) have been included therein on the authority
of "experts"  within the meaning of the Securities  Act, we are not such experts
with respect to any portion of the  Registration  Statement,  including  without
limitation  the  financial  statements  or  schedules  or  the  other  financial
information or data included therein.

                                                Very truly yours,



                                                /s/ MULDOON, MURPHY & FAUCETTE