1
                                                                     EXHIBIT 5.1

                                January 14, 1998

Integrated Silicon Solution, Inc.
2231 Lawson Lane
Santa Clara, CA 95054

        RE:    REGISTRATION STATEMENT ON FORM S-8

Ladies and Gentlemen:

        We have examined the Registration Statement on Form S-8 to be filed by
you with the Securities and Exchange Commission on or about January 14, 1998
(the "Registration Statement") in connection with the registration under the
Securities Act of 1933, as amended (the "Act"), of 1,193,500 shares of your
Common Stock issuable under your Nonstatutory Stock Plan. Such shares of Common
Stock are referred to herein as the "Shares" and the Nonstatutory Stock Plan is
referred to herein as the "Plan". As your counsel in connection with this
transaction, we have examined the proceedings taken and are familiar with the
proceedings proposed to be taken by you in connection with the issuance and sale
of the Shares pursuant to the Plan.

        It is our opinion that, upon completion of the actions being taken, or
contemplated by us as your counsel to be taken by you prior to the issuance of
the Shares pursuant to the Registration Statement and the Plan and upon
completion of the actions being taken in order to permit such transactions to be
carried out in accordance with the securities laws of the various states where
required, the Shares will be legally and validly issued, fully-paid and
non-assessable.

        We consent to the use of this opinion as an exhibit to the Registration
Statement, and further consent to the use of our name wherever appearing in the
Registration Statement and any amendments thereto.

                                         Very truly yours,

                                         WILSON SONSINI GOODRICH & ROSATI
                                         Professional Corporation

                                         /s/ Wilson Sonsini Goodrich & Rosati