<DOCUMENT>
<TYPE>EX-8
<SEQUENCE>3
<FILENAME>d83242ex8.txt
<DESCRIPTION>PROPOSED TAX OPINION OF BRUNINI GRANTHAM GROWER
<TEXT>

<PAGE>   1


                                                                       EXHIBIT 8

              [BRUNINI, GRANTHAM, GROWER & HEWES, PLLC LETTERHEAD]

                              ______________, 2001

Board of Directors Trustmark Corporation
248 East Capitol Street, Suite 300
Jackson, Mississippi  39201

Board of Directors and Shareholders Barret Bancorp, Inc.

          Re:  Merger Agreement by and among Trustmark Corporation, Trustmark
               National Bank, Barret Bancorp, Inc., Peoples Bank and Somerville
               Bank & Trust Company

Gentlemen:

      We have acted as counsel to Trustmark Corporation, a Mississippi
corporation and registered bank holding company ("Trustmark"), and Trustmark
National Bank, a national banking association ("Trustmark Bank"), in connection
with the proposed Merger (the "Merger") of Barret Bancorp, Inc. ("Barret"), a
Tennessee corporation, with Trustmark under the charter of Trustmark and the
merger of Peoples Bank ("Peoples") with Trustmark Bank under the charter of
Trustmark Bank (the "Bank Merger") pursuant to the terms of the Merger Agreement
dated as of December 12, 2000 (the "Merger Agreement"), by and among Trustmark,
Trustmark Bank, Barret, Peoples and Somerville Bank & Trust Company
("Somerville"), each as described in the Registration Statement on Form S-4
filed by Trustmark with the Securities and Exchange Commission (the
"Registration Statement"). All capitalized terms, unless otherwise specified,
have the meanings assigned to them in the Registration Statement.

      In connection with this opinion, we have examined and are familiar with
originals or copies, certified or otherwise identified to our satisfaction, of
(i) the Merger Agreement, (ii) the Registration Statement, and (iii) such other
documents as we have deemed necessary or appropriate in order to enable us to
render the opinions below. In our examination, we have assumed the genuineness
of all signatures, the legal capacity of all natural persons, the authenticity
of all documents submitted to us as originals, the conformity to original
documents of all documents submitted to us as certified, conformed or
photostatic copies and the authenticity of the originals of such copies. In
rendering the opinions set forth below, we have relied upon certain written
representations and covenants of Trustmark and Trustmark Bank, Barret and
Barret's shareholders.

      In rendering our opinion, we have considered the applicable provisions of
the Internal Revenue Code of 1986, as amended (the "Code"), existing and
proposed Treasury Regulations, pertinent judicial authorities, interpretive
rulings of the Internal Revenue Service and such other authorities as we have
considered relevant. The following opinion is based upon the foregoing
authorities as existing on the date of this opinion. In addition, any change in
the facts and assumptions upon which this opinion is based could modify the
conclusions reached herein.

      Our opinion covers only the matters expressly set forth herein, and no
opinions should be inferred as to any other matters or as to any other tax
aspects of the above-described transactions that are not specifically addressed.

      Based upon and subject to the foregoing, we are of the opinion that the
Merger will, under current law, constitute a tax-free reorganization under
Section 368(a)(1)(A) of the Code and the Bank Merger will, under current law,
constitute a tax-free reorganization under both Sections 368(a)(1)(A) and
368(a)(1)(D). It is further our opinion that Trustmark and Barret will be
parties to the Merger and Trustmark Bank and Peoples will each be a party to the
Bank Merger.

      As a tax-free reorganization, the Merger and the Bank Merger will have the
following Federal income tax consequences for Barret and its shareholders and
Trustmark and Trustmark Bank:

<PAGE>   2


        1. No gain or loss will be recognized by the holders of the common stock
of Barret as a result of the exchange of such shares for shares of Trustmark
common stock ("Trustmark Common Stock") pursuant to the Merger. Cash received by
any Barret shareholder as a consequence of the election to do so or as a
consequence of perfecting dissenters' rights of appraisal with respect to their
Barret shares will be treated as having been received by such shareholders as a
distribution in redemption of his or her stock, subject to the provisions and
limitations of Code Section 302. The payment of cash in lieu of fractional share
interests will be treated as if the shares were distributed as part of the
exchange and then were redeemed by Trustmark. These cash payments will be
treated as distributions in full payment in exchange for the stock redeemed,
subject to the provisions and limitations of Code Section 302.

        2. The tax basis of the shares of Trustmark Common Stock received by
shareholders of Barret will equal the tax basis of such shareholder's shares of
Barret (reduced by any amount allocable to fractional share interests for which
cash is received) exchanged in the Merger, decreased by the amount of cash
received by the shareholder and increased by the amount which was treated as a
dividend and the amount of any gain recognized on the exchange and not treated
as a dividend.

        3. The holding period for the shares of Trustmark Common Stock received
by each shareholder of Barret will include the holding period for the shares of
Barret exchanged in the Merger, provided that the shares of Barret stock is held
as a capital asset in the hands of such shareholder of Barret on the effective
date of the Merger.

        4. No gain or loss will be recognized by Trustmark or by Barret on the
transfer of all of Barret's assets to Trustmark in exchange for the Common Stock
(distributed to the Barret shareholders) and the assumption by Trustmark of the
liabilities of Barret and the liabilities to which the transferred assets are
subject.

        5. No gain or loss will be recognized by Trustmark Bank or by Peoples on
the transfer of all of Peoples' assets to Trustmark Bank in the Bank Merger and
the assumption by Trustmark Bank of the liabilities of Peoples and the
liabilities to which the transferred assets are subject.

        Except as set forth above, we express no opinion as to the tax
consequences to any party, whether Federal, state, local or foreign, of the
Merger, or of any transactions related to the Merger, or contemplated by the
Merger Agreement. This opinion is being furnished only to you in connection with
the Merger and solely for your benefit in connection therewith and may not be
used or relied upon for any other purpose and may not be circulated, quoted or
otherwise referred to for any other purpose without our express written consent.

Very truly yours,

BRUNINI, GRANTHAM, GROWER & HEWES, PLLC



Louis G. Fuller

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