Exhibit 5.1

                         [Andrea D. Kantor Letterhead]

                                                               July 8, 2005

GSE Systems, Inc.
9189 Red Branch Road
Columbia, MD  21045

Gentlemen:

     Reference is made to the Registration Statement on Form S-3 of GSE Systems,
Inc. (the "Company") relating to the registration of shares of Common Stock, par
value $.01 per share (the "Common Stock"), of the Company.

     I am General  Counsel of the  Company,  and have  examined  such  corporate
records and other documents as I have deemed  relevant.  Based upon the above, I
am of the opinion that the shares of Common Stock to be distributed  pursuant to
the Registration Statement have been authorized, validly issued, fully paid, and
non-assessable.

     I hereby  consent  to the  filing  of this  opinion  as an  exhibit  to the
Registration  Statement and the use of my name in the Prospectus included in the
Registration Statement.

                                        Very truly yours,


                                        Andrea D. Kantor