EXHIBIT 99.1


                                       April 11, 2000


Dear Participant:

         As of March 29, 2000, the trust ("DRP Trust") established for the
Columbia Federal Savings Bank (now known as CFS Bank, the "Bank") Recognition
and Retention Plan for Outside Directors ("DRP") held 13,982 shares of common
stock of Haven Bancorp, Inc. (the "Company"), the parent holding company for the
Bank. As a participant in the DRP, you may direct the voting of the shares of
the Company's common stock held by the DRP Trust that have been granted to you
under the DRP.

         Chase Manhattan Bank has been appointed as an unrelated corporate
trustee for the DRP Trust (the "DRP Trustee"). We, the Board of Directors, are
forwarding to you the attached Vote Authorization Form, provided for the purpose
of conveying your voting instructions to the DRP Trustee. The DRP Trustee will
vote those shares of the Company's common stock held in the DRP Trust that have
been granted to participants in accordance with instructions received from the
participants. If the DRP Trustee does not receive voting instructions with
respect to shares that have been granted to participants, the DRP Trustee will
vote such shares in the same proportion as it votes the shares for which it has
received voting instructions.

         At this time to direct the voting of shares granted to you under the
DRP, you must complete and sign the enclosed Vote Authorization Form and return
it in the accompanying envelope to Ellen Philip Associates, Inc. ("Ellen Philip
Associates"). Your vote will not be revealed, directly or indirectly, to any
director, officer or other employee of the Company or the Bank. Your shares will
be tallied by Ellen Philip Associates on a confidential basis. Ellen Philip
Associates will then provide the tabulated results to the DRP Trustee. The DRP
Trustee will then vote the shares in the DRP Trust based on the voting
instructions it has received from participants, as described above.



                                         Sincerely,




                                         The Board of Directors







                               HAVEN BANCORP, INC.

                         ANNUAL MEETING OF STOCKHOLDERS
                                  MAY 17, 2000

                             VOTE AUTHORIZATION FORM

I, having signed this form, hereby instruct the Columbia Federal Savings Bank
Recognition and Retention Plan for Outside Directors ("DRP") Trustee to vote all
shares of common stock of Haven Bancorp, Inc. granted to me under the DRP as set
forth below at the Annual Meeting of Stockholders to be held on May 17, 2000,
and at any adjournment or postponement thereof.

                                             Please  mark your
                                             votes as             /X/
                                             indicated in
                                             this example


                 THE BOARD OF DIRECTORS RECOMMENDS A VOTE "FOR"
                          EACH OF THE LISTED PROPOSALS.

1.   The Election as directors of all nominees listed: (Except as marked to the
     contrary below)

     Philip S. Messina, Msgr. Thomas J. Hartman, Michael A. McManus, Jr.

         FOR                                                  VOTE WITHHELD
         / /                                                   / /

INSTRUCTION: To withhold your vote for any individual nominee, write that
nominee's name on the space provided below:

- --------------------------------------------

2.   The ratification of the appointment of KPMG LLP as independent auditors of
     Haven Bancorp, Inc. for the fiscal year ending December 31, 2000.

         FOR                  AGAINST                       ABSTAIN
         / /                  / /                             / /

I acknowledge that I have received from the Company prior to the execution of
this vote authorization form, a Notice of Annual Meeting of Stockholders, a
Proxy Statement dated April 11, 2000, the Annual Report to Stockholders and a
letter dated April 11, 2000 from the Board of Directors.

I understand that my voting instructions are solicited by the Board of Directors
on behalf of the DRP Trustee for the Annual Stockholders Meeting to be held on
May 17, 2000, and at any adjournment or postponement thereof. The DRP Trustee is
hereby authorized to vote the shares granted to me, in its trust capacity, as
indicated above.


                                            ----------------------------------
                                            Signature
- ------------------------
Date

Please sign, date and return this form in the enclosed business reply envelope.