EXHIBIT 5.1

October 14, 2004

Accelrys, Inc.
9685 Scranton Road
San Diego, California 92121

Ladies and Gentlemen:

        We have examined the Registration Statement on Form S-3 to be filed by you with the Securities and Exchange Commission on or about the date hereof (the "Registration Statement") in connection with the registration under the Securities Act of 1933, as amended, of an aggregate of 1,374,390 shares of your Common Stock (the "Shares"). All of the Shares are issued and outstanding and may be offered for sale for the benefit of the selling stockholders named in the Registration Statement. The Shares are to be sold from time to time as described in the Registration Statement. As your legal counsel, we have examined the proceedings taken by you in connection with the issuance of the Shares.

        It is our opinion that the Shares are legally and validly issued, fully paid and nonassessable.

        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 it appears in the Registration Statement, including the prospectus constituting a part thereof, and any amendments thereto.