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            EXHIBIT 5     OPINION OF MULDOON, MURPHY & FAUCETTE LLP




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                  [MULDOON, MURPHY & FAUCETTE LLP LETTERHEAD]



                                 April 18, 2000



Board of Directors
PFSB Bancorp, Inc.
123 W. Lafayette Street, P.O. Box 72
Palmyra, Missouri 63461-0072

      Re:   PFSB Bancorp, Inc. 2000 Stock-Based Incentive Plan
            Registration Statement on Form S-8 for Offer and Sale of
            78,260 Shares of Common Stock

Ladies and Gentlemen:

         We have been  requested by PFSB Bancorp,  Inc., a Missouri  corporation
(the  "Company"),  to issue a legal opinion in connection with the  registration
(the  "Registration")  of 78,260 shares of the Company's Common Stock,  $.01 par
value  (the  "Shares"),  on Form S-8  under  the  Securities  Act of  1933.  The
Registration  covers 55,900 Shares that may be issued upon the exercise of stock
options and 22,360 Shares that may be  distributed  as  restricted  stock awards
under the PFSB Bancorp, Inc 2000 Stock-Based Incentive Plan (the "Plan").

      As such  counsel,  we have made such legal and  factual  examinations  and
inquiries as we deemed  advisable for the purpose of rendering this opinion.  In
our  examination,  we have assumed and have not verified (i) the  genuineness of
all  signatures,  (ii) the  authenticity  of all  documents  submitted  to us as
originals,  (iii) the conformity with the originals of all documents supplied to
us as copies,  and (iv) the accuracy and  completeness of all corporate  records
and documents and of all certificates and statements of fact, in each case given
or made available to us by the Company or its subsidiary.

      Based on the  foregoing and limited in all respects to Missouri law, it is
our opinion that the Shares  reserved  under the Plan have been duly  authorized
and, upon the issuance of the Shares in the manner  described in the Plan, will,
when granted, be validly issued, fully paid and nonassessable.





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Board of Directors
PFSB Bancorp, Inc.
April 18, 2000
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      We hereby  consent to the filing of this opinion as an exhibit to, and the
reference to this firm in, the Company's Registration Statement on Form S-8, and
we consent to the use of the name of our firm under the  heading  "Interests  of
Named Experts and Counsel".

                                         Very truly yours,

                                         /s/ Muldoon, Murphy & Faucette LLP
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                                         MULDOON, MURPHY & FAUCETTE LLP