<PAGE>   1
                                                                Exhibit 5
                           [BROWN & BAIN LETTERHEAD]


                                 March 5, 1997

                       Prologic Management Systems, Inc.
                       Registration Statement on Form S-8
             Covering Shares Issuable Under 1994 Stock Option Plan

Ladies and Gentlemen:

        We have acted as counsel to Prologic Management Systems, Inc., an
Arizona corporation (the "Company"), in connection with the registration under
the Securities Act of 1933, as amended (the "Securities Act"), of 500,000
shares (the "Shares") of the Company's common stock, without par value (the
"Common Stock"), which may be issued from time to time upon the exercise of
stock options granted pursuant to the Company's 1994 Stock Option Plan (the
"Plan"). The Shares are being registered pursuant to a registration statement
on Form S-8 (the "Registration Statement") filed with the Securities and
Exchange Commission (the "Commission"). This letter is Exhibit 5 to the
Registration Statement.

        In arriving at the opinion expressed below, we have examined the
Registration Statement and such other documents, including the Articles of
Incorporation and Bylaws of the Company, each as amended to date, as we have
deemed necessary to enable us to express the opinion set forth herein. In
addition, we have examined and relied on the originals or copies, certified or
otherwise identified to our satisfaction as conforming to the originals thereof,
of such other documents and corporate records of the Company and such other
instruments and certificates of public officials and other persons as we have
deemed appropriate. We have assumed the authenticity of all documents submitted
to us as originals, the conformity to the original documents of all documents
submitted to us as copies, and the genuineness of all signatures on all
documents reviewed by us.

        Based on the foregoing and subject to the limitations and
qualifications set forth herein, we are of the opinion that:

        The Shares of Common Stock to be issued by the Company pursuant to the
Registration Statement have been duly authorized, and upon issuance and
delivery in accordance with the terms of the Plan will be duly and validly
issued and fully paid and nonassessable.

<PAGE>   2
                         [BROWN & BAIN P.A. LETTERHEAD]

Prologic Management
Systems, Inc.                         -2-                          March 4, 1997


     This opinion is limited to the present laws of the State of Arizona and the
present federal laws of the United States and to the facts as they presently
exist. We hereby consent to references to our firm under the caption "Legal
Matters" in the Registration Statement and to the use of this opinion as an
exhibit to 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, or the rules and regulations of the
Commission thereunder.

                                                Very truly yours,

                                                /s/ Brown & Bain, P.A.
                                                ------------------------
                                                Brown & Bain, P.A.

Prologic Management Systems, Inc.
  2030 East Speedway Boulevard
    Tucson, Arizona 85719