EXHIBIT 5.1


                                        August 21, 1997


Reliance Bancorp, Inc.
585 Stewart Avenue
Garden City, New York 11530

Ladies and Gentlemen:

         We have acted as special counsel for Reliance Bancorp, Inc., a Delaware
corporation ("Reliance"), and Reliance Federal Savings Bank, a federally
chartered stock form savings bank and wholly-owned subsidiary of Reliance
("Reliance Bank"), in connection with the issuance of and registration under the
Securities Act of 1933, as amended, by Reliance of an aggregate of
1,013,909 shares, subject to adjustment, of Reliance common stock, par
value $0.01 per share (the "Merger Shares"), into which certain shares of common
stock, par value $5.00 per share, of Continental Bank, a New York State
chartered commercial bank ("Continental"), will be converted pursuant to an
Agreement and Plan of Merger, dated as of May 3, 1997 and amended as of July 1,
1997, by and among Reliance, Reliance Bank and Continental (as amended, the
"Merger Agreement"), and the related preparation and filing by Reliance with the
Securities and Exchange Commission of a registration statement on Form S-4 (the
"Registration Statement"). In rendering the opinions set forth below, we do not
express any opinion concerning law other than the federal law of the United
States and the corporate law of the State of Delaware.

         We have examined originals or copies, certified or otherwise identified
to our satisfaction, of such documents, corporate records and other instruments,
and have examined such matters of law, as we have deemed necessary or advisable
for purposes of rendering the opinions set forth below. As to matters of fact,
we have examined and relied upon the representations of Reliance, Reliance Bank
and Continental contained in the Merger Agreement and the Registration Statement
and, where we have deemed appropriate, representations or certificates of
officers of Reliance, Reliance Bank or Continental or public officials. We have
assumed the authenticity of all documents submitted to us as originals, the
genuineness of all signatures, the legal capacity of natural persons and the
conformity to the originals of all documents submitted to us as copies. In
making our examination of any documents, we have assumed that all parties, other
than Reliance and Reliance Bank, had the corporate power and authority to enter
into and perform all obligations thereunder, and, as to such parties, we have
also assumed the due authorization by all





Reliance Bancorp, Inc.
August 21, 1997                                                          Page 2.


requisite action, the due execution and delivery of such documents and the
validity and binding effect and enforceability thereof.

         Based on the foregoing, we are of the opinion that, upon effectiveness
of the Registration Statement the issuance of the Merger Shares in accordance
with the terms of the Merger Agreement will have been duly authorized and, when
the Merger Shares are issued in accordance with the terms of the Merger
Agreement and the Registration Statement, the Merger Shares will be validly
issued, fully paid and non-assessable.

         In rendering the opinions set forth above, we have not passed upon and
do not purport to pass upon the application of "doing business" or securities or
"blue-sky" laws of any jurisdiction (except federal securities laws).

         This opinion is given solely for the benefit of Reliance and
Continental and the shareholders of Continental who exchange shares of
Continental common stock for the Merger Shares pursuant to the Registration
Statement, and may not be relied upon by any other person or entity, nor quoted
in whole or in part, or otherwise referred to in any document without our
express written consent.

         We consent to the filing of this opinion as an Exhibit to the
Registration Statement and to the reference to our firm under the headings "THE
MERGER -- Material Federal Income Tax Consequences" and "LEGAL MATTERS" in the
Proxy Statement-Prospectus that is part of such Registration Statement.

                                       Very truly yours,

                                       THACHER PROFFITT & WOOD


                                       By: /s/ Omer S.J. Williams
                                           Omer S.J. Williams