Exhibit 8.1

                        [LETTERHEAD OF BINGHAM DANA LLP]

                                                              January 23, 2002

First Financial Corp.
180 Washington Street
Providence, RI  02903

Ladies and Gentlemen:

         This opinion is furnished to you pursuant to Section 7.01(f) of the
Agreement and Plan of Merger dated as of November 12, 2001, as clarified by a
letter agreement dated January 22, 2002 (as so clarified, the "AGREEMENT"),
by and among Washington Trust Bancorp, Inc., a Rhode Island corporation
("BUYER"), and First Financial Corp., a Rhode Island corporation ("SELLER").
Pursuant to the Agreement, Seller will merge with and into Buyer in a
transaction (the "MERGER") in which the existing stockholders of Seller will
receive shares of Buyer Common Stock (including the common share purchase
rights attached thereto and referred to in the Agreement) and cash in
exchange for their shares of Seller Common Stock. You have requested our
opinion as to certain federal income tax consequences anticipated to follow
from implementation of the Agreement. Capitalized terms not defined herein
have the respective meanings set forth in the Agreement.

         For purposes of our opinion, we have examined and relied upon the
originals or copies, certified or otherwise identified to us to our
satisfaction, of the Agreement, the proxy statement/prospectus included in the
Registration Statement on Form S-4 (file No. 333-76258), as amended, filed with
the Securities and Exchange Commission on January 23, 2002, by Buyer in
connection with the Merger (the "REGISTRATION STATEMENT"), and related documents
(the Agreement, the Registration Statement, and such related documents are
referred to herein collectively as the "DOCUMENTS"). In that examination, we
have assumed the genuineness of all signatures, the authenticity and
completeness of all documents purporting to be originals (whether reviewed by us
in original or copy form), and the conformity to the originals of all documents
purporting to be copies, including electronic copies.

         As to certain factual matters, we have relied with your consent upon,
and our opinion is limited by, the representations and statements of the various
parties set forth in the Documents and in the certificates from Buyer and Seller
dated the date hereof, copies of which are attached hereto (the "CERTIFICATES").
Our opinion assumes (i) that all representations and statements set forth in the
Documents and in the Certificates are true, correct, and complete as of the
dates made and as of the date hereof, and (ii) that those representations and
statements will remain true, correct and




First Financial Corp.
January 23, 2002
Page 2

complete at all times through and including the Effective Time. Our opinion is
limited solely to the provisions of the federal Internal Revenue Code as now in
effect (the "Code") and the regulations, rulings, and interpretations thereof in
force as of this date. We assume no obligation to address other facts or to
advise you of changes in the law or in the interpretation thereof that occur
after the date of this opinion.

         On the basis of and subject to the foregoing, assuming due adoption and
implementation of the Agreement in accordance with its terms and consistent with
the representations set out in the Documents and Certificates (and without any
waiver or modification of any thereof), we are of the opinion that for United
States federal income tax purposes the Merger will constitute a reorganization
within the meaning of Section 368(a) of the Code.

         This opinion is being delivered solely to you for your use in
connection with the Merger. It may not be made available to or relied upon by
any other person or entity or used for any other purpose without our prior
written consent. We hereby consent to the use of our name in the Registration
Statement under the captions "Material United States Federal Income Tax
Consequences" and "Legal Matters" and to the filing of this opinion as an
exhibit to the Registration Statement.


                                                     Very truly yours,



                                                     /s/ BINGHAM DANA LLP