Exhibit 5.1

                      [BROWN & WOOD LLP LETTERHEAD]



                                   March 6, 1998



BankBoston Corporation
100 Federal Street
Boston, MA  02110


Ladies and Gentlemen:

     This  opinion is delivered in connection with the Registration Statement
on Form  S-3 (File  Nos. 333-47125, 333-47125-01  and 333-47125-02)  filed on
February 27, 1998, as amended by Pre-Effective Amendment  No. 1 thereto filed
March  6,  1998  (the  "Registration  Statement"),  with the  Securities  and
Exchange Commission (the  "Commission") under the Securities Act  of 1933, as
amended  (the  "Act"),   by  the  BankBoston  Corporation,   a  Massachusetts
corporation ("Corporation"), and  BankBoston Capital Trust IV  and BankBoston
Capital Trust V, each  a Delaware business trust (the "Trusts",  and together
with  the  Corporation,  the  "Registrants"),  which  Registration  Statement
relates to  (i) preferred  securities to  be  issued by  each  of the  Trusts
representing  beneficial  ownership  interests  in  the  related  Trust  (the
"Capital   Securities"),   (ii) junior   subordinated   deferrable   interest
debentures to be  issued by the Corporation (the  "Debentures") in connection
with  the  issuance  of  Capital  Securities  by  the  applicable  Trust  and
(iii) guarantees  to  be  issued by  the  Corporation  (the  "Guarantees") in
respect of certain obligations  of each of the Trusts  under their respective
Capital Securities. 

     We have examined an executed copy of  the Registration Statement and all
exhibits  thereto,  including (i)  the  form of  Indenture  (the "Indenture")
between the Corporation and The Bank  of New York, as Debenture Trustee  (the
"Debenture Trustee"), pursuant to which  the Debentures are to be  issued and
(ii) the  form  of  Capital  Security  Guarantee  Agreement  (the  "Guarantee
Agreement") between  the Corporation and The  Bank of New York,  as Guarantee
Trustee (the  "Guarantee Trustee"). In  addition, we have examined,  and have
relied  as to  matters  of  fact  upon, originals  or  copies,  certified  or
otherwise   identified  to  our  satisfaction,  of  such  corporate  records,
agreements,   documents  and  other  instruments  and  such  certificates  or
comparable documents of  public officials and of officers and representatives
of the Corporation, and have made such other and further investigations, as 
we  have deemed  relevant and  necessary as a  basis for the  opinions 
hereinafter set forth.

     In our examination,  we have assumed the genuineness  of all signatures,
the  legal capacity  of natural  persons, the  authenticity of  all documents
submitted to  us as originals,  the conformity to  original documents of  all
documents  submitted  to us  as  certified  or  photostatic copies,  and  the
authenticity of the originals of such latter documents.  We have also assumed
that  the Registration  Statement will  have become  effective under  the Act
prior to the time of issuance,  offering and sale of any Capital  Securities,
Debentures or Guarantees.

     Based  upon  the  foregoing,  and  subject  to  the  qualifications  and
limitations stated herein, we are of the opinion that:

          1.   With  respect to the  Debentures to be  issued under each
     Indenture,  such  Debentures  have  been  duly  authorized  by  the
     Corporation and, when  (i) such Indenture has been  duly authorized
     and validly  executed and delivered  by the Corporation and  by the
     Debenture Trustee and (ii) such Debentures have been duly executed,
     authenticated,  issued  and   delivered  in  accordance  with   the
     provisions  of such  Indenture upon  payment  of the  consideration
     therefor  as  contemplated  by  the  Registration  Statement,  such
     Debentures will constitute valid and legally binding obligations of
     the Corporation, enforceable against the Corporation in  accordance
     with their terms.

          2.  With  respect to the  Guarantee to  be issued  under each
     Guarantee Agreement, such Guarantee has been duly authorized by the
     Corporation  and, when  such  Guarantee  Agreement  has  been  duly
     authorized  and validly executed  and delivered by  the Corporation
     and by the  Guarantee Trustee as  contemplated in the  Registration
     Statement,  such  Guarantee  will constitute  a  valid  and legally
     binding  obligation  of the  Corporation,  enforceable against  the
     Corporation in accordance with its terms.

     Our  opinions set forth in  paragraphs 1 and 2 above  are subject to the
effects  of  bankruptcy, insolvency,  fraudulent  conveyance, reorganization,
moratorium and other similar laws  relating to or affecting creditors' rights
generally  and  general  principles  of   equity  (whether  considered  in  a
proceeding in equity or at law).

     We are members of  the Bar of the  State of New  York and we express  no
opinion as to the laws of any  jurisdiction other than the laws of the  State
of New York and the  federal laws of the United  States of America and,  with
respect to  the laws of  the Commonwealth of  Massachusetts, we have  made no
independent  investigation  of such  laws  and  have  relied on  all  matters
governed  by such laws upon the opinion of Gary A. Spiess, General Counsel of
the Corporation.

     We  hereby consent to the  filing of this  opinion as an  exhibit to the
Registration  Statement and to  the reference to  our firm under  the caption
"Validity of Securities" contained in the Prospectus included therein.


                                        Very truly yours,


                                        /s/ Brown & Wood LLP

                                        BROWN & WOOD LLP