Bingham McCutchen LLP
                               150 Federal Street
                                Boston, MA 02460


November 24, 2004

VIA EDGAR

Division of Investment Management
Securities and Exchange Commission
901 E Street, N.W.
Washington, D.C. 20004
    Attn.: Patricia Williams

          Re:  Domini Social Investment Trust (File No. 33-29180)
               --------------------------------------------------

Dear Ms. Williams:

This letter relates to the Domini Social Investment Trust (the "Registrant") and
follows up on telephone conversations we had on November 15, 2004 and on
November 19, 2004 regarding the Post-Effective Amendment filed by the Registrant
on September 29, 2004 (the "Registration Statement").

Below are the comments that you raised and the Registrant's responses thereto.

1.   You noted that you were making a "Tandy" letter comment, consistent with
     the current practice of the staff (the "Staff") of the Securities and
     Exchange Commission (the "Commission").

     RESPONSE: Attached hereto is a letter from the Registrant to the Commission
     that contains certain acknowledgements requested by the Staff.

2.   In the Prospectus, you asked that the disclosure regarding automatic
     clearing house ("ACH") transactions be revised to clarify that purchases
     are priced at the net asset value next determined after receipt of the
     order in accordance with Rule 22c-1(a) under the Investment Company Act of
     1940, as amended (the "1940 Act").

     RESPONSE: As provided in the Prospectus, orders received by 4:00 p.m. will
     receive the NAV determined at the end of that day. The Registrant has
     revised the disclosure regarding ACH transactions to reflect that ACH
     transactions are not considered to be in good order until payment for the
     purchased shares is received by the Funds and that this may take up to 48
     hours.

3.   In the Prospectus, you asked that the language on page A-5 of the
     Shareholder Manual to the effect that shares purchased by check may not be
     available to be sold for up to 8 business days after purchase be revised to
     reflect, as provided elsewhere in the




Page 2


     Prospectus, that such shares can be sold but that the payment of the
     redemption proceeds may be delayed until the check clears.

     RESPONSE: The Registrant has made the requested revision.

4.   In the Statement of Additional Information, you noted that the fundamental
     policy of the Domini Social Equity Fund allowed the Fund to invest more
     than 25% of its assets in stocks of a single industry if the stocks of such
     industry comprise more than 25% of the Domini 400 Social Index (the
     "Index"). You also noted that the composition of the Index is maintained by
     KLD Research & Analytics, Inc. ("KLD") and asked why Ms. Domini's position
     with both the advisor and KLD does not create a situation where the advisor
     would have the freedom to concentrate in an industry.

     RESPONSE: Ms. Domini is not the CEO of, and does not have any other
     position with, KLD. As reflected in the description of her principal
     occupations during the past five years in the Statement of Additional
     Information, she served as the CEO, Secretary and Treasurer of KLD from
     1990 to 2000.

5.   In the table included in the Statement of Additional Information labeled
     "Trustees and Officers of the Trust and the Portfolio" you asked that the
     column labeled "Principal Occupation(s) During Past 5 Years and Other
     Directorships Held" be split into two columns as required by Form N-1A.

     RESPONSE: The Registrant has revised the table so that there is a column
     for "Principal Occupations During the Past 5 Years" and a column for "Other
     Directorships Held by Trustee".

6.   In the Statement of Additional Information, you asked that the disclosure
     regarding the distribution plan included under the heading "Distributor" be
     revised in light of the requirements of Item 14(g)(1) of Form N-1A.

     RESPONSE: The Registrant has revised the disclosure as requested.

We hope that this information addresses your comments with respect to the
Registration Statement. If you should have any further questions, please do not
hesitate to contact me at 617-951-8760.

                                                 Sincerely,

                                                 /s/ Toby R. Serkin
                                                 Toby R. Serkin


cc:  Elizabeth L. Belanger




                         Domini Social Investment Trust
                             536 Broadway, 7th Floor
                            New York, New York 10012


November 24, 2004

Division of Investment Management
Securities and Exchange Commission
901 E Street, N.W.
Washington, D.C. 20004
    Attn.: Ms. Patricia Williams

          Re:  Domini Social Investment Trust (File No. 33-29180)
               --------------------------------------------------

Dear Ms. Williams:

     In response to a comment from the staff (the "Staff") of the Securities and
Exchange Commission (the "Commission") in connection with its review of the
Post-Effective Amendment filed by the Domini Social Investment Trust (the
"Registrant") on September 29, 2004 (the "Registration Statement"), the
Registrant acknowledges that, with respect to filings made by the Registrant
with the Commission and reviewed by the Staff:

     (a) the Registrant is responsible for the adequacy and accuracy of the
disclosure in the filings;

     (b) Staff comments or changes to disclosure in response to Staff comments
in the filings reviewed by the Staff do not foreclose the Securities and
Exchange Commission from taking any action with respect to the filings; and

     (c) the Registrant may not assert Staff comments as a defense in any
proceeding initiated by the Commission or any person under the federal
securities laws of the United States.

                                              Best regards,

                                              Domini Social Investment Trust


                                                  By: /s/ Carole M. Laible
                                                      --------------------------
                                                      Carole M. Laible
                                                      Treasurer