EXHIBIT 5.1




                                   May 5, 1999

Summit Design, Inc.
9305 S.W. Gemini Drive
Beaverton, OR  97008

     RE:  REGISTRATION STATEMENT ON FORM S-8

Ladies and Gentlemen:

     We have examined the Registration Statement on Form S-8 (the 
"Registration Statement") to be filed by Summit Design, Inc., a Delaware 
corporation (the "Registrant" or "you"), with the Securities and Exchange 
Commission on or about May 5, 1999, in connection with the registration under 
the Securities Act of 1933, as amended (the "1933 Act"), of an aggregate of 
235,000 shares of your Common Stock, $0.01 par value (the "Shares"), reserved 
for issuance pursuant to the 1996 Employee Stock Purchase Plan (the "Plan").  
As your legal counsel, we have examined the proceedings taken and are 
familiar with the proceedings proposed to be taken by you in connection with 
the sale and issuance of the Shares by the Registrant under the Plan.

     It is our opinion that the Shares will be, when issued and sold in the
manner referred to in the Plan, legally 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 appearing in the
Registration Statement and any subsequent amendment thereto.


               Very truly yours,

               WILSON SONSINI GOODRICH & ROSATI
               Professional Corporation

               /s/  Wilson Sonsini Goodrich & Rosati