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                        Quickturn Design Systems, Inc.
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               (Name of Registrant as Specified In Its Charter)            
                                                                           
                                                                           
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                [LETTERHEAD OF QUICKTURN DESIGN SYSTEMS, INC.]

CONTACTS:

     QUICKTURN DESIGN SYSTEMS, INC.             ABERNATHY MACGREGOR FRANK
     Joan Powell                                Pauline Yoshihashi
     Director, Marketing Communications         (213) 630-6550
     (408) 914-6701                             Matt Sherman
     joan@quickturn.com                         (212) 371-5999


FOR IMMEDIATE RELEASE


           QUICKTURN RESPONDS TO MENTOR GRAPHICS' EXTENSION OF ITS 
                           UNSOLICITED TENDER OFFER

               QUICKTURN'S BOARD CONTINUES TO STRONGLY RECOMMEND
              THAT QUICKTURN STOCKHOLDERS NOT TENDER THEIR SHARES

SAN JOSE, CALIF. (DECEMBER 1, 1998)--Quickturn Design Systems, Inc. (Nasdaq:
QKTN) today responded to Mentor Graphics Corporation's (Nasdaq: MENT) extension
of its tender offer, which was scheduled to expire November 30, 1998, but was
extended by Mentor to December 21, 1998 without its purchasing any shares
tendered.  Mentor continues to own only 591,500 shares of Quickturn stock.
Quickturn's board continues to strongly recommend that Quickturn stockholders
not tender their shares to Mentor and urges Quickturn stockholders who may have
tendered to withdraw their shares.

     On August 24, 1998, the Quickturn board of directors recommended that
Quickturn stockholders reject Mentor's unsolicited tender offer.  The board
determined that Mentor's offer is inadequate, does not reflect the inherent
value of the Company, and is not in the best interests of Quickturn or its
stockholders.  Quickturn's board considered, among other things, the historical
trading prices of Quickturn's common stock, including the fact that Mentor's
offer is more than 25% below the stock's highest closing price over the last
year, and less than 4% above its average closing price during the same period.

     Quickturn Design Systems, Inc. is the leading provider of verification
products and time-to-market engineering (TtME/TM/) services for the design of
complex ICs and electronic systems. The company's products are used worldwide by
developers of high-performance computing, multimedia, graphics and
communications systems. Quickturn is headquartered at 55 W. Trimble Road, San
Jose, CA 95131-1013; Telephone: 408/914-6000. For more information, visit the
Quickturn Web site at www.quickturn.com or send e-mail to info@quickturn.com.

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