Exhibit (i)(2)


                                                October 31, 2002


State Street Institutional Investment Trust
P.O. Box 1713
Boston, MA 02105-1713

Ladies and Gentlemen:

     We have acted as counsel to State Street Institutional Investment Trust
(the "Trust"). In connection with this opinion, we have examined:

     (a)  A copy of the Agreement and Declaration of Trust of the Trust, dated
          February 16, 2000 (the "Declaration of Trust"), certified by the
          Secretary of the Trust;

     (b)  A copy of Amendment No. 1 to the Declaration of Trust, dated February
          14, 2002, certified by the Secretary of the Trust;

     (c)  A certificate of the Secretary of State of the Commonwealth of
          Massachusetts dated October 28, 2002 certifying as to the authority of
          the Trust to exercise in The Commonwealth all of the powers recited in
          the Declaration of Trust, as amended, and to transact business in The
          Commonwealth; and that the Trust has filed the necessary certificates
          required to be filed in The Commonwealth and paid the necessary fees
          due thereon;

     (d)  A copy of the By-Laws of the Trust certified by the Secretary of the
          Trust;

     (e)  A certificate of the Secretary of the Trust dated October 31, 2002 as
          to, among other things, certain actions of the Trustees of the Trust;
          and

     (f)  Such other certificates, documents, and records as we have deemed
          necessary for purposes of this opinion.

     In our examination, we have assumed the genuineness of all signatures, the
legal capacity of all 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 made such examination of Massachusetts law as we have deemed
relevant for purposes of this opinion. We express no opinion as to the effect of
laws, rules, and regulations of any state or jurisdiction other than The
Commonwealth of Massachusetts.

     You have advised us that the Trust has filed with the Securities and
Exchange Commission a registration statement and amendments thereto (the
"Registration Statement") under the Securities Act of 1933, as amended (the
"1933 Act"), relating to the issuance of shares of beneficial interest of
various series of the Fund, including the State Street Money Market Fund (such
shares of beneficial interest of the State Street Money Market Fund referred to
herein as the "Shares").

     For purposes of this opinion, we have assumed that all Shares will be
offered and sold on the terms, and that the Trust will receive for the sale of
such Shares the consideration, set forth in the Registration Statement as in
effect at the time of such sale, and that such consideration will be in each
case at least equal to the applicable net asset value per Share.

     We assume that appropriate action has been taken to register or qualify the
sale of the Shares under any applicable state and federal laws regulating
offerings and sales of securities.

     Based upon and subject to the foregoing, we are of the opinion that:

     1.   The Trust is a legally organized and validly existing voluntary
association with transferable shares of beneficial interest under the laws of
The Commonwealth of Massachusetts and is authorized to issue an unlimited number
of Shares.

     2.   Shares issued and sold after the date hereof will be validly issued,
fully paid, and nonassessable by the Trust.

     The Trust is an entity of the type commonly known as a "Massachusetts
business trust". Under Massachusetts law, shareholders could, under certain
circumstances, be held personally liable for the obligations of the Trust.
However, the Declaration of Trust, as amended, disclaims shareholder liability
for any credit, contract, or claim of or against the Trust or any series of the
Trust and requires that notice of such disclaimer be given in every note, bond,
contract, instrument, certificate, or undertaking made or issued on behalf of
the Trust by its Trustees or officers or otherwise. The Declaration of Trust, as
amended, provides for indemnification out of the property of the series in
question for all loss and expense of any shareholder of that series held
personally liable for the obligations of the series solely by reason of his
being or having been a shareholder of the series. Thus, the risk of a
shareholder's incurring financial loss on account of shareholder liability is
limited to circumstances in which the series in question itself would be unable
to meet its obligations.

     We consent to the filing of this opinion as an exhibit to the Registration
Statement.

                                                  Very truly yours,

                                                  /s/ Ropes & Gray
                                                  Ropes & Gray