<PAGE>

                                 UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549
                                  FORM 10-K/A

(Mark One)
     [X]  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                     SECURITIES EXCHANGE ACT OF 1934
                For the fiscal year ended December 31, 1998
                                      OR
     [ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                     SECURITIES EXCHANGE ACT OF 1934
          For the transition period from ___________ to __________

                        Commission file number:  1-6522

                            BANKBOSTON CORPORATION
            (Exact name of Registrant as specified in its charter)


         Massachusetts                                       04-2471221
(State or other jurisdiction of                           (I.R.S. Employer
 incorporation or organization)                          Identification No.)

100 Federal Street, Boston, Massachusetts                      02110
(Address of principal executive offices)                     (Zip Code)

Registrant's telephone number, including area code:        (6l7) 434-2200

          Securities registered pursuant to Section 12(b) of the Act:
                     -------------------------------------
Title of each class
    -------------
Common Stock, par value $1.00 per share
Preferred Stock Purchase Rights

                   Name of each exchange on which registered:
                          ---------------------------
Each class is registered on the New York Stock Exchange and the Boston Stock
Exchange
       Securities registered pursuant to Section 12(g) of the Act:  None
                     -------------------------------------
Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the Registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.
  Yes [X]  No [ ]

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K ((S) 229.405 of this chapter) is not contained herein, and
will not be contained, to the best of Registrant's knowledge, in definitive
proxy or information statements incorporated by reference in Part III of this
Form 10-K or any amendment to this Form 10-K.  [ ]

Aggregate market value of shares of common      Number of shares of common
     stock held by non-affiliates of             stock outstanding as of
     Registrant as of March 1, 1999                   March 1, 1999
     ------------------------------                   -------------
     $12,027,433,486                                  296,482,247

Documents Incorporated by Reference:
-----------------------------------
1.   Pertinent extracts from Registrant's 1998 Annual Report to Stockholders
     (Parts I, II and IV).
2.   Pertinent extracts from Registrant's Proxy Statement in connection with the
     Registrant's 1999 Annual Meeting of Stockholders (Part III).
<PAGE>

                                    PART IV

Item 14.   Exhibits, Financial Statement Schedules, and Reports on Form 8-K.

(a)(1) The financial statements required in response to this Item are
incorporated by reference from Item 8 of this Report.

(a)(2) Financial statement schedules have been omitted because the information
is either not required, not applicable, or is included in the financial
statements or notes thereto.

(a)(3)    Exhibits

   ++3(a) - Restated Articles of Organization of the Corporation, effective
            as of November 18, 1998.

     3(b) - By-Laws of the Corporation, as amended through January 1, 1998,
            incorporated herein by reference to Exhibit 3(b) to the
            Corporation's Annual Report on Form 10-K for the year ended December
            31, 1997 (File No. 1-6522).

     4(a) - There are no agreements with respect to the long-term debt of the
            Corporation authorizing the issuance of securities in an amount
            exceeding 10% of the total assets of the Corporation and its
            subsidiaries on a consolidated basis. The Corporation agrees to
            furnish a copy of any agreement defining the rights of the holders
            of the Corporation's long-term debt to the Securities and Exchange
            Commission upon request.

     4(b) - Rights Agreement, as amended through December 12, 1995, between the
            Corporation and the Bank, as Rights Agent, and the description of
            the Rights, incorporated herein by reference to the Corporation's
            registration statement on Form 8-A relating to the Rights, Exhibit 1
            to such registration statement and Exhibit 4(g) to the Corporation's
            Annual Report on Form 10-K for the year ended December 31, 1995
            (File No. 1-6522).

     4(c) - Renewed Rights Agreement, dated as of December 17, 1998, between the
            Corporation and the Bank, as Rights Agent, incorporated herein by
            reference to Exhibit 4 to the Corporation's Current Report on Form
            8-K dated December 17, 1998 (File No. 1-6522).

    10(a) - BankBoston Corporation 1982 Stock Option Plan, as amended through
            October 23, 1997, incorporated herein by reference to Exhibit 10(a)
            to the Corporation's Annual Report on Form 10-K for the year ended
            December 31, 1997 (File No. 1-6522).*

-----------------------------------------------
++ Indicates that the exhibit was previously filed with the Form 10-K and is not
   being filed with this Form 10-K/A.
*  Indicates that document is a management contract or compensatory plan or
   arrangement that is required to be filed as an exhibit to the 10-K Report
   pursuant to Item 14(c) of Form 10-K.

                                       2
<PAGE>

(a)(3) Exhibits (cont'd)

    10(b) - BankBoston Corporation 1986 Stock Option Plan, as amended through
            October 23, 1997, incorporated herein by reference to Exhibit 10(b)
            to the Corporation's Annual Report on Form 10-K for the year ended
            December 31, 1997 (File No. 1-6522).*

    10(c) - BankBoston Corporation 1991 Long-Term Stock Incentive Plan, as
            amended through October 23, 1997, incorporated herein by reference
            to Exhibit 10(c) to the Corporation's Annual Report on Form 10-K for
            the year ended December 31, 1997 (File No. 1-6522).*

  ++10(d) - BankBoston Corporation 1996 Long-Term Incentive Plan, as amended
            through June 25, 1998.*

  ++10(e) - BankBoston Corporation and its Subsidiaries Performance
            Recognition Opportunity Plan, as amended effective June 9, 1998.*

    10(f) - BankBoston Corporation Executive Deferred Compensation Plan, as
            amended, effective June 23, 1994, incorporated herein by reference
            to Exhibit 10(d) to the Corporation's Annual Report on Form 10-K for
            the year ended December 31, 1994 (File No. 1-6522).*

    10(g) - BankBoston, N.A. Bonus Supplemental Employee Retirement Plan, as
            amended through June 23, 1994, incorporated herein by reference to
            Exhibit 10(e) to the Corporation's Annual Report on Form 10-K for
            the year ended December 31, 1994 (File No. 1-6522).*

    10(h) - Description of the Corporation's Supplemental Life Insurance Plan,
            incorporated herein by reference to Exhibit 10(h) to the
            Corporation's Annual Report on Form 10-K for the year ended December
            31, 1988 (File No. 1-6522).*

    10(i) - BankBoston, N.A. Excess Benefit Supplemental Employee Retirement
            Plan, as amended, effective June 23, 1994, incorporated herein by
            reference to Exhibit 10(g) to the Corporation's Annual Report on
            Form 10-K for the year ended December 31, 1994 (File No. 1-6522).*

  ++10(j) - BankBoston Corporation Relocation Policy, as amended effective
            January 1, 1999.*

-----------------------------------------------
++ Indicates that the exhibit was previously filed with the Form 10-K and is not
   being filed with this Form 10-K/A.
*  Indicates that document is a management contract or compensatory plan or
   arrangement that is required to be filed as an exhibit to the 10-K Report
   pursuant to Item 14(c) of Form 10-K.

                                       3
<PAGE>

(a)(3) Exhibits (cont'd)

    10(k) - Description of the Corporation's Supplemental Long-Term Disability
            Plan, effective as of February 10, 1994, incorporated herein by
            reference to Exhibit 10(l) to the Corporation's Annual Report on
            Form 10-K for the year ended December 31, 1993 (File No. 1-6522).*

  ++10(l) - BankBoston Corporation's Director Stock Award Plan, as amended
            effective July 1, 1998.*

  ++10(m) - Form of Severance Agreement for members of the Office of the
            Chief Executive Officer and certain other officers.*

  ++10(n) - Form of Severance Agreement for other officers.*

    10(o) - BankBoston Corporation Directors Deferred Compensation Plan,
            effective March 28, 1991, incorporated herein by reference to
            Exhibit 10(q) to the Corporation's Annual Report on Form 10-K for
            the year ended December 31, 1994 (File No. 1-6522).*

    10(p) - BankBoston, N.A. Directors Deferred Compensation Plan, effective
            March 28, 1991, incorporated herein by reference to Exhibit 10(r) to
            the Corporation's Annual Report on Form 10-K for the year ended
            December 31, 1994 (File No. 1-6522).*

    10(q) - BankBoston Corporation 1997 Stock Option Plan for Non-Employee
            Directors, effective as of April 1, 1997, incorporated herein by
            reference to Exhibit 10(q) to the Corporation's Annual Report on
            Form 10-K for the year ended December 31, 1997 (File No. 1-6522).*

    10(r) - Description of the Corporation's Director Retirement Benefits
            Exchange Program, incorporated herein by reference to Exhibit 10(r)
            to the Corporation's Annual Report on Form 10-K for the year ended
            December 31, 1997 (File No. 1-6522).*

    10(s) - 1988 Stock Option Plan for Key Employees of BayBanks, Inc., and
            Affiliates, as amended through October 23, 1987, incorporated herein
            by reference to Exhibit 10.2 to BayBanks' Quarterly Report on Form
            10-Q for the quarter ended September 30, 1994 (File No. 0-959) and
            Exhibit 10(u) to the Corporation's Annual Report on Form 10-K for
            the year ended December 31, 1997 (File No. 1-6522).*

-----------------------------------------------
++  Indicates that the exhibit was previously filed with the Form 10-K and is
    not being filed with this Form 10-K/A.
*   Indicates that document is a management contract or compensatory plan or
    arrangement that is required to be filed as an exhibit to the 10-K Report
    pursuant to Item 14(c) of Form 10-K.

                                       4
<PAGE>

(a)(3) Exhibits (cont'd)

    10(t) - BayBanks Supplemental Executive Retirement Plan, as amended through
            November 27, 1996, incorporated herein by reference to Exhibit 19.6
            to BayBanks' Quarterly Report on Form 10-Q for the quarter ended
            June 30, 1991, Exhibit 10.8 to BayBanks' Annual Report on Form 10-K
            for the year ended December 31, 1991, Exhibit 10.2 to BayBanks'
            Quarterly Report on Form 10-Q for the quarter ended June 30, 1994
            and Exhibit 10.8 to BayBanks' Quarterly Report on Form 10-Q for the
            quarter ended September 30, 1994 (File No. 0-959) and to Exhibits
            10(y) and 10(z) to the Corporation's Annual Report on Form 10-K for
            the year ended December 31, 1996 (File No. 1-6522).*

    10(u) - BayBanks Profit Sharing Excess Benefit Plan, as amended,
            incorporated herein by reference to Exhibit 10.1 to BayBanks'
            Quarterly Report on Form 10-Q for the quarter ended March 31, 1993
            and Exhibit 10.1 to BayBanks' Quarterly Report on Form 10-Q for the
            quarter ended June 30, 1994 (File No. 0-959).*

    10(v) - BayBanks Deferred Payment Plans Trust Agreement, as amended through
            October 27, 1994, incorporated herein by reference to Exhibit 19 to
            BayBanks' Quarterly Report on Form 10-Q for the quarter ended June
            30, 1992 and Exhibit 10.10 to BayBanks' Quarterly Report on Form
            10-Q for the quarter ended September 30, 1994 (File No. 0-959).*

    10(w) - Consulting Agreement, dated as of December 30, 1997, between the
            Corporation and William M. Crozier, Jr., incorporated herein by
            reference to Exhibit 10(aa) to the Corporation's Annual Report on
            Form 10-K for the year ended December 31, 1997 (File No. 1-6522).*

    10(x) - Letter Agreement, dated as of August 15, 1997, between the
            Corporation and Henrique de Campos Meirelles, incorporated herein by
            reference to Exhibit 10(bb) to the Corporation's Annual Report on
            Form 10-K for the year ended December 31, 1997 (File No. 1-6522).*

    10(y) - Lease, as amended through October 1, 1997, between BankBoston, N.A.
            and Equitable Federal Street Realty Company Limited Partnership,
            incorporated herein by reference to Exhibit 10(l) to the
            Corporation's Annual Report on Form 10-K for the year ended December
            31, 1991, to Exhibits 10(gg), 10(hh), 10(ii), 10(jj) and 10(kk) to
            the Corporation's Annual Report on Form 10-K for the year ended
            December 31, 1996, and to Exhibits 10(cc), 10(dd), 10(ee), 10(ff)
            and 10(gg) to the Corporation's Annual Report on Form 10-K for the
            year ended December 31, 1997 (File No. 1-6522).

-----------------------------------------------
*   Indicates that document is a management contract or compensatory plan or
    arrangement that is required to be filed as an exhibit to the 10-K Report
    pursuant to Item 14(c) of Form 10-K.

                                       5
<PAGE>

(a)(3) Exhibits (cont'd)

  ++12(a) - Computation of the Corporation's Consolidated Ratio of Earnings
            to Fixed Charges (excluding interest on deposits).

  ++12(b) - Computation of the Corporation's Consolidated Ratio of Earnings
            to Fixed Charges (including interest on deposits).

  ++13(a) - Pages 21 through 58 and 60 through 89 of the Corporation's 1998
            Annual Report to Stockholders.

    13(b) - Corrected Page 60 of the Corporation's 1998 Annual Report to
            Stockholders.

  ++21    - List of subsidiaries of BankBoston Corporation.

  ++23    - Consent of Independent Accountants.

  ++24    - Power of attorney of certain officers and directors.

  ++27    - Financial Data Schedule

    99    - Notice of Annual Meeting and Proxy Statement for the Annual Meeting
            of the Corporation's Stockholders held April 22, 1999, incorporated
            herein by reference to the Corporation's filing under Regulation 14A
            of the Exchange Act (File No. 1-6522).

      (b) - During the fourth quarter of 1998, the Corporation filed two Current
            Reports on Form 8-K. The current reports, dated October 15, 1998 and
            December 17, 1998, each contained information pursuant to items 5
            and 7 of Form 8-K. The Corporation also filed two Current Reports on
            Form 8-K, dated January 21, 1999 and February 3, 1999, each of which
            contained information pursuant to items 5 and 7 of Form 8-K.

-----------------------------------------------
++ Indicates that the exhibit was previously filed with the Form 10-K and is not
   being filed with this Form 10-K/A.
*  Indicates that document is a management contract or compensatory plan or
   arrangement that is required to be filed as an exhibit to the 10-K Report
   pursuant to Item 14(c) of Form 10-K.

                                       6
<PAGE>

                                   SIGNATURES

     Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this amendment on
Form 10-K/A to the Annual Report on Form 10-K for the year ended December 31,
1998 to be signed on its behalf by the undersigned, thereunto duly authorized,
in the City of Boston, and the Commonwealth of Massachusetts, on the 22nd day of
June, 1999.

                                BANKBOSTON CORPORATION


                                   By: /s/ Robert T. Jefferson
                                       --------------------------
                                       (Robert T. Jefferson)
                                       (Comptroller)
                                       (Chief Accounting Officer)


     Pursuant to the requirements of the Securities Exchange Act of 1934, this
amendment on Form 10-K/A to the Annual Report on Form 10-K for the year ended
December 31, 1998 has been signed by the following persons in the capacities and
on the dates listed below.

<TABLE>
<CAPTION>
Signature                              Title                     Date
------------------------------------   ---------------------     --------------
<S>                                    <C>                       <C>
/s/ CHARLES K. GIFFORD*                Chairman and Chief        June 22, 1999
-----------------------                Executive Officer and
(Charles K. Gifford)                   Director (Chief
                                       Executive Officer)

/s/ HENRIQUE DE CAMPOS MEIRELLES*      President and Chief       June 22, 1999
---------------------------------      Operating Officer and
(Henrique de Campos Meirelles)         Director

/s/ SUSANNAH M. SWIHART*               Vice Chairman, Chief      June 22, 1999
---------------------------------      Financial Officer and
(Susannah M. Swihart)                  Treasurer (Chief
                                       Financial Officer)

/s/ ROBERT T. JEFFERSON                Comptroller               June 22, 1999
---------------------------------      (Chief Accounting
(Robert T. Jefferson)                  Officer)
</TABLE>

                                      II-1
<PAGE>

<TABLE>
<CAPTION>
Signature                              Title                     Date
------------------------------------   ---------------------     --------------
<S>                                    <C>                       <C>
/s/ WAYNE A. BUDD*                     Director                  June 22, 1999
---------------------------------
(Wayne A. Budd)

                                       Director                  June   , 1999
---------------------------------
(Daniel P. Burnham)

/S/ WILLIAM F. CONNELL*                Director                  June 22, 1999
---------------------------------
(William F. Connell)

/S/ GARY L. COUNTRYMAN*                Director                  June 22, 1999
---------------------------------
(Gary L. Countryman)


/S/ ALICE F. EMERSON*                  Director                  June 22, 1999
---------------------------------
(Alice F. Emerson)

/S/ THOMAS J. MAY*                     Director                  June 22, 1999
---------------------------------
(Thomas J. May)

/S/ DONALD F. MCHENRY*                 Director                  June 22, 1999
---------------------------------
(Donald F. McHenry)

/S/ THOMAS R. PIPER*                   Director                  June 22, 1999
---------------------------------
(Thomas R. Piper)

/S/ FRANCENE S. RODGERS*               Director                  June 22, 1999
---------------------------------
(Francene S. Rodgers)


/S/ JOHN W. ROWE*                      Director                  June 22, 1999
---------------------------------
(John W. Rowe)


/S/ GLENN P. STREHLE*                  Director                  June 22, 1999
---------------------------------
(Glenn P. Strehle)

/S/ WILLIAM C. VAN FAASEN*             Director                  June 22, 1999
---------------------------------
(William C. Van Faasen)

/S/ THOMAS B. WHEELER*                 Director                  June 22, 1999
---------------------------------
(Thomas B. Wheeler)

/S/ ALFRED M. ZEIEN*                   Director                  June 22, 1999
---------------------------------
(Alfred M. Zeien)

*By:  /s/ ROBERT T. JEFFERSON
      ------------------------
      Attorney-in-fact
</TABLE>

                                     II-2