EXHIBIT 5

              Letterhead of Arent Fox Kintner Plotkin & Kahn, PLLC

                                February 5, 2004

The Board of Directors
GTSI Corp.
3901 Stonecroft Boulevard
Chantilly, Virginia 20151-1010

Gentlemen:

         We have acted as counsel to GTSI Corp. (the "Company") with respect to
the Company's Registration Statement on Form S-8, filed by the Company with the
Securities and Exchange Commission in connection with the registration under the
Securities Act of 1933, as amended, of 323,000 shares of Common Stock, par value
$.005 per share (the "Shares"), subject to issuance pursuant to Nonqualified
Stock Option Agreements between the Company and Christopher Tully, Amy Squires,
Steve Hammond, John McClung, Jr., Lauren Kovach, Marc Lieberman, John Helmly,
James Todd Leto, Thomas Mutryn, Robert Mitchell, Paul Liberty, Frank Blaul,
Craig Ballam, and John Littley, III (the "Stock Option Agreements").

         As counsel to the Company, we have examined the Company's Certificate
of Incorporation, as amended, and such records, certificates and other documents
of the Company, as well as relevant statutes, regulations, published rulings and
such questions of law, as we considered necessary or appropriate for the purpose
of this opinion.

         We assume that, prior to the sale of any Shares to which the
Registration Statement relates, appropriate action will be taken to register and
qualify such Shares for sale, to the extent necessary, under any applicable
state securities laws.

         Based on the foregoing, we are of the opinion that the 323,000 Shares
subject to the Stock Option Agreements when issued or delivered and paid for in
accordance with the terms of their respective Stock Option Agreements, will be
validly issued, fully paid and nonassessable.

         We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to all references to our firm in the Registration
Statement. In giving this consent, we do not hereby admit that we come within
the category of persons whose consent is required under Section 7 of the
Securities Act of 1933, as amended, or the General Rules and Regulations
thereunder.


                                          Very truly yours,



                                          Arent Fox Kintner Plotkin & Kahn, PLLC