Exhibit 5.1



                               September 12, 2001



ANSYS, Inc.
275 Technology Drive - Southpointe
Canonsburg, Pennsylvania  15317

                    Re:  Registration Statement On Form S-8
                         ----------------------------------

Ladies and Gentlemen:

         I am Corporate  Counsel of ANSYS, Inc. (the "Company") and I have acted
as counsel for the Company in connection  with the  preparation  of the Form S-8
Registration  Statement  to be filed by the  Company  with  the  Securities  and
Exchange  Commission for the  registration  under the Securities Act of 1933, as
amended,  of an additional  1,000,000  shares of the Company's common stock, par
value $.01 per share (the  "Shares"),  which are to be offered from time to time
to certain  officers,  employees  and  directors of the Company  pursuant to the
terms of the  Company's  1996  Stock  Option  Plan and Grant,  as  amended  (the
"Plan"),  and which may be sold by such  officers,  employees and directors from
time to time hereafter.

         I have examined the  originals,  certified  copies or copies  otherwise
identified  to my  satisfaction  as being true copies of the Plan and such other
documents  as I have  deemed  necessary  or  appropriate  for  purposes  of this
opinion.

         Based on the  foregoing,  I am of the opinion that the Shares have been
duly and validly  authorized  and reserved for  issuance  and,  when issued upon
exercise  of options  granted  under the Plan and  pursuant  to the terms of the
Plan, will be legally and validly issued, fully paid and nonassessable.

          I hereby  consent to the filing of this  opinion as Exhibit 5.1 to the
Registration Statement.

                                            Very truly yours,

                                            /s/ David Secunda

                                            David Secunda