EXHIBIT 5.1

                 OPINION OF MALIZIA, SPIDI, SLOANE & FISCH, P.C.
                     AS TO THE VALIDITY OF THE COMMON STOCK
                                BEING REGISTERED





                      MALIZIA, SPIDI, SLOANE & FISCH, P.C.
                                ATTORNEYS AT LAW
                               1301 K STREET, N.W.
                                 SUITE 700 EAST
                             WASHINGTON, D.C. 20005
                                 (202) 434-4660
                            FACSIMILE: (202) 434-4661


March 17, 1999



Board of Directors
Advance Financial Bancorp
1015 Commerce Street
Wellsburg, West Virginia  26070

            RE:            Registration Statement on Form S-8:
                           ----------------------------------
                           Advance Financial Bancorp 1998 Stock Option Plan

Gentlemen:

     We have acted as special counsel to Advance Financial  Bancorp,  a Delaware
corporation  (the  "Company"),   in  connection  with  the  preparation  of  the
Registration  Statement on Form S-8 to be filed with the Securities and Exchange
Commission (the  "Registration  Statement") under the Securities Act of 1933, as
amended,  relating to 108,445  shares of common stock,  par value $.10 per share
(the  "Common  Stock") of the Company  which may be issued upon the  exercise of
options granted or which may be granted under the Advance Financial Bancorp 1998
Stock Option Plan (the  "Plan"),  as more fully  described  in the  Registration
Statement.  You have  requested the opinion of this firm with respect to certain
legal aspects of the proposed offering.

     We have examined  such  documents,  records,  and matters of law as we have
deemed  necessary for purposes of this opinion and based thereon,  we are of the
opinion that the Common Stock when issued  pursuant to the stock awards  granted
under and in  accordance  with the  terms of the Plan  will be duly and  validly
issued, fully paid, and nonassessable.

     We hereby  consent  to the  filing of this  opinion  as an  exhibit  to the
Registration Statement on Form S-8.

                                     Sincerely,

                                     /s/   Malizia, Spidi, Sloane & Fisch, P.C.
                                     -----------------------------------------

                                     Malizia, Spidi, Sloane & Fisch, P.C.