EXHIBIT 5.1

               [LETTERHEAD OF STRADLING, YOCCA, CARLSON & RAUTH]


                               February 5, 1997


Helisys, Inc.
24015 Garnier Street
Torrance, California 90505

          RE:  Registration Statement on Form S-8 - 1995 Stock Incentive Plan

Ladies and Gentlemen:

     At your request, we have examined the form of Registration Statement on
Form S-8, (the "Registration Statement"), being filed by Helisys, Inc., a
Delaware corporation (the "Company"), with the Securities and Exchange
Commission (the "Commission") on February 5, 1997, in connection with
the registration under the Securities Act of 1933, as amended, of an aggregate
of 500,000 shares of the Company's Common Stock, $.001 par value per share (the
"Common Stock"), issuable under the Company's 1995 Stock Incentive Plan, as
amended (the "Plan").

     We have examined the proceedings heretofore taken and are familiar with the
additional proceedings proposed to be taken by the Company in connection with
the authorization, issuance and sale of the securities referred to above.

     Based on the foregoing, it is our opinion that the 500,000 shares of Common
Stock to be issued under the Plan and against full payment therefor in
accordance with the respective terms and conditions of the Plan will be legally
and validly issued, fully paid and nonassessable.

 
Helisys, Inc.
February 5, 1997
Page 2


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


                              Very truly yours,

                              STRADLING, YOCCA, CARLSON & RAUTH