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      EXHIBIT 5.0 OPINION OF MULDOON, MURPHY & FAUCETTE RE:  LEGALITY


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                                 August 27, 1997



Board of Directors
BostonFed Bancorp, Inc.
17 New England Executive Park
Burlington, Massachusetts  01803

         Re:   BostonFed Bancorp, Inc. 1997 Stock Option Plan

Ladies and Gentlemen:

         We have been requested by BostonFed  Bancorp,  Inc. (the  "Company") to
issue a legal opinion in connection with the  registration  under the Securities
Act of 1933 on Form S-8 of 250,000  shares of the Company's  Common Stock,  $.01
par value (the "Shares"),  to be issued under the BostonFed  Bancorp,  Inc. 1997
Stock Option Plan (the "Plan").

         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, Boston Federal Savings Bank.

         Based on the  foregoing and limited in all respects to Delaware law, it
is our opinion that the Shares reserved under the Plan have been duly authorized
and upon payment for and  issuance of the Shares in the manner  described in the
Plan, will be legally issued, fully paid and nonassessable.

         The following provisions of the 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 Common Stock:




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Board of Directors
August 27, 1997
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         (a)  Subsections C.3 and C.6 of Article FOURTH and Section D of Article
EIGHTH, which grant the Board the authority to construe and apply the provisions
of  those  Articles,  subsection  C.4 of  Article  FOURTH,  to the  extent  that
subsection  obligates  any person to provide to the Board the  information  such
subsection  authorizes the Board to demand,  and the provision of Section C.7 of
Article  EIGHTH  authorizing  the Board to  determine  the Fair Market  Value of
property  offered or paid for the Company's stock by an Interested  Stockholder,
in each case to the extent,  if any, that a court applying  Delaware law were to
impose equitable limitations upon such authority; 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.

         We hereby  consent to the  filing of this  opinion as an exhibit to the
Company's  Registration  Statement on Form S-8, and we consent to the use of our
name under the heading "Interests of Named Experts and Counsel."


                                             Sincerely,

                                             /s/ MULDOON, MURPHY & FAUCETTE
                                             -----------------------------------
                                                 MULDOON, MURPHY & FAUCETTE