[LETTERHEAD OF VORYS, SATER, SEYMOUR AND PEASE LLP]

                                  July 30, 1999




Board of Directors
Peoples Bancorp Inc.
138 Putnam Street
Marietta, OH  45750

Gentlemen:

                  In connection with the  registration  under the Securities Act
of 1933, as amended (the "1933 Act"),  of (a)  $30,000,000  aggregate  principal
amount of Series B 8.62% Junior Subordinated Deferrable Interest Debentures (the
"New  Junior  Subordinated   Debentures")  of  Peoples  Bancorp  Inc.,  an  Ohio
corporation  ("Peoples"),  to be issued  pursuant to the terms of the  Indenture
dated as of April 20, 1999 (the  "Indenture"),  between  Peoples and  Wilmington
Trust Company,  as Debenture  Trustee;  (b)  $30,000,000  aggregate  liquidation
amount of Series B 8.62% Capital  Securities  (the "New Capital  Securities") of
PEBO Capital  Trust I, a business  trust  created under the laws of the State of
Delaware (the  "Trust"),  to be issued  pursuant to the terms of the Amended and
Restated  Declaration  of Trust,  dated as of April 20, 1999 (the  "Amended  and
Restated Declaration of Trust"),  among Peoples and Wilmington Trust Company, as
Property Trustee and as Delaware Trustee, and the Administrative  Trustees named
therein;  and (c) the Series B Capital Securities Guarantee Agreement related to
the New Capital Securities (the "New Guarantee") to be executed and delivered by
Peoples  for the  benefit of the  holders  from time to time of the New  Capital
Securities,   we,  as  your  counsel,  have  examined  such  corporate  records,
certificates  and  other  documents,  and  such  questions  of  law,  as we have
considered  necessary or appropriate  for the purposes of this opinion.  We have
also relied as to certain  matters  related to Peoples on  information  obtained
from public  officials,  officers of Peoples and other sources believed by us to
be responsible.

                  In our examinations, we have assumed and have not verified (i)
the  legal  capacity  of  all  natural  persons,  (ii)  the  genuineness  of all
signatures,  (iii)  the  authenticity  of  all  documents  submitted  to  us  as
originals,  (iv) the conformity to original documents of all documents submitted
to us as copies and the authenticity of the originals of such latter  documents,
and (v) 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  Peoples.  In making our  examination  of  documents  executed or to be
executed by parties  other than  Peoples,  we have assumed that such parties had
the  power,  corporate  or other,  to enter  into and  perform  all  obligations
thereunder,  and we have assumed the due  authorization by all requisite action,
corporate  or other,  and valid  execution  and delivery by such parties of such
documents  and the  validity,  binding  effect and  enforceability  thereof with
respect to such parties.

                  We have neither examined,  nor do we opine upon, any provision
or  matter  to the  extent  that the  examination  or  opinion  would  require a
financial, mathematical or accounting calculation or determination.

                  Upon the basis of such examination, we advise you that, when:

                           (i)  the   Registration   Statement   on   Form   S-4
         ("Registration  No. 333-81251),  as amended by Pre-Effective  Amendment
         No. 1  thereto  (the  "Registration  Statement"),  relating  to the New
         Junior Subordinated Debentures,  the New Capital Securities and the New
         Guarantee has become effective under the 1933 Act;

                           (ii)  the  Series  B  Capital  Securities   Guarantee
         Agreement relating to the New Guarantee with respect to the New Capital
         Securities of the Trust has been duly executed and delivered;

                           (iii) the New  Junior  Subordinated  Debentures  have
         been duly executed and  authenticated  in accordance with the Indenture
         and issued and delivered as contemplated in the Registration Statement;
         and

                           (iv)  the  New  Capital  Securities  have  been  duly
         executed in  accordance  with the Amended and Restated  Declaration  of
         Trust of the Trust and  issued and  delivered  as  contemplated  in the
         Registration Statement,

the New Junior Subordinated Debentures and the New Guarantee relating to the New
Capital  Securities  of the Trust  will  constitute  valid and  legally  binding
obligations of Peoples, subject to the limitations,  if any, of Title 11 U.S.C.,
as amended,  and of the  applicable  insolvency,  reorganization,  moratorium or
other laws  affecting  the  enforcement  of creditors'  rights  generally and by
principles of equity.  We advise you that certain  remedial and other provisions
of the New Junior  Subordinated  Debentures  (and the Indenture under which they
may be issued) and the New Guarantee may be limited by (i) implied  covenants of
good faith,  fair dealing and  commercially  reasonable  conduct,  (ii) judicial
discretion,  in the instance of multiple or equitable remedies, and (iii) public
policy.

                  We understand that you have received an opinion  regarding the
New Capital  Securities from Richards,  Layton & Finger,  P.A., special Delaware
counsel for Peoples and the Trust.  We are expressing no opinion with respect to
the matters contained in such opinion.

                  Members  of our firm are  admitted  to the bar in the State of
Ohio and we express no  opinion as to the laws of any other  jurisdiction  other
than the laws of the United States. We note that each of the Indenture,  the New
Junior Subordinated Debentures, and the New Guarantee is governed by the laws of
the State of New York.  For purposes of this  opinion,  we have assumed that the
laws of the State of New York are not inconsistent  with the laws of Ohio in any
matter material to this opinion.

                  We hereby  consent to the filing of this opinion as an exhibit
to Pre-Effective  Amendment No. 1 to the Form S-4 Registration  Statement and to
the references to us under the heading  "Legal  matters" in the  Prospectus.  In
giving  such  consent,  we do not thereby  admit that we are in the  category of
persons whose consent is required under Section 7 of the 1933 Act.



                                Very truly yours,

                            /s/ VORYS, SATER, SEYMOUR AND PEASE LLP
                                -----------------------------------
                                Vorys, Sater, Seymour and Pease LLP