RICHARDS, LAYTON & FINGER LETTERHEAD




                                                    July 29, 1999






PEBO Capital Trust I
_ Peoples Bancorp Inc.
138 Putnam Street
Marietta, Ohio 45750

                  Re:      PEBO Capital Trust I
                  -----------------------------

Ladies and Gentlemen:

                  We have acted as special  Delaware  counsel  for PEBO  Capital
Trust I, a Delaware  business trust (the "Trust"),  and Peoples Bancorp Inc., an
Ohio  corporation  (the  "Company"),  in  connection  with the matters set forth
herein. At your request, this opinion is being furnished to you.

                  For purposes of giving the opinions hereinafter set forth, our
examination  of documents  has been limited to the  examination  of originals or
copies of the following:

(1)      The   Certificate   of  Trust  of  the   Trust   (the "Certificate"),
         as  filed  in  the  office  of  the Secretary  of State of the  State
         of  Delaware  (the "Secretary of State") on April 13, 1999;

(2)      The Original Declaration of Trust, dated as of April 13, 1999, among
         the Company and the trustees named therein;

(3)      The  Amended  and  Restated   Declaration   of  Trust (including Annex
         1 and the Exhibits  thereto),  dated as of April 20,  1999 (the
         "Declaration  of Trust"), among the Company,  as Sponsor,  the
         trustees  named therein (the "Trustees") and the holders from time to
         time of undivided beneficial interests in the Trust;


(4)      The   Registration   Statement   (the   "Registration Statement")  on
         Form  S-4,  including  a  preliminary prospectus (the "Prospectus")
         relating to the Series B 8.62% Capital  Securities of the Trust
         representing undivided  beneficial interests in the Trust (each, a
         "Series B Capital  Security"  and  collectively,  the "Series  B
         Capital  Securities"),  as  filed  by the Company  and  the  Trust
         with  the   Securities  and Exchange Commission on June 22, 1999; and

(5)      A Certificate of Good Standing for the Trust, dated June 21, 1999,
         obtained from the Secretary of State.

                  Initially  capitalized  terms used  herein and not otherwise
defined are used as defined in the  Declaration  of Trust.

                  For  purposes  of this  opinion,  we  have  not  reviewed  any
documents other than the documents  listed above, and we have assumed that there
exists no provision in any document that we have not reviewed that bears upon or
is  inconsistent   with  the  opinions  stated  herein.  We  have  conducted  no
independent factual  investigation of our own but rather have relied solely upon
the foregoing  documents,  the statements and  information set forth therein and
the additional  matters recited or assumed herein,  all of which we have assumed
to be true, complete and accurate in all material respects.

                  With respect to all documents  examined by us, we have assumed
(i) the  authenticity of all documents  submitted to us as authentic  originals,
(ii) the  conformity  with the  originals  of all  documents  submitted to us as
copies or forms, and (iii) the genuineness of all signatures.


                  For  purposes of this  opinion,  we have  assumed (i) that the
Declaration of Trust  constitutes the entire agreement among the parties thereto
with  respect to the  subject  matter  thereof,  including  with  respect to the
creation,  operation and  termination of the Trust,  and that the Declaration of
Trust  and the  Certificate  are in full  force  and  effect  and  have not been
amended,  (ii)  except to the extent  provided  in  paragraph  1 below,  the due
creation or due  organization  or due  formation,  as the case may be, and valid
existence in good standing of each party to the  documents  examined by us under
the laws of the jurisdiction governing its creation,  organization or formation,
(iii) the legal  capacity of natural  persons  who are parties to the  documents
examined by us, (iv) that each of the  parties to the  documents  examined by us
has the  power  and  authority  to  execute  and  deliver,  and to  perform  its
obligations  under,  such documents,  (v) the due  authorization,  execution and
delivery  by all  parties  thereto of all  documents  examined  by us,  (vi) the
receipt by each  Person to whom a Series B Capital  Security  is to be issued by
the Trust (collectively,  the "Series B Capital Security Holders") of a Series B
Capital Security  Certificate for such Series B Capital Security in exchange for
a Series A Capital Security, in accordance with the Declaration of Trust and the
Prospectus,  and (vii) that the Series B Capital  Securities  will be  executed,
authenticated  and issued to the Series B Capital Security Holders in accordance
with the  Declaration of Trust and the Prospectus.  We have not  participated in
the  preparation of the  Registration  Statement or the Prospectus and assume no
responsibility for their contents.

                  This  opinion is limited to the laws of the State of  Delaware
(excluding  the  securities  laws of the  State  of  Delaware),  and we have not
considered  and  express  no  opinion  on the  laws of any  other  jurisdiction,
including federal laws and rules and regulations  relating thereto. Our opinions
are  rendered  only with  respect to Delaware  laws and rules,  regulations  and
orders thereunder which are currently in effect.

                  Based upon the  foregoing,  and upon our  examination  of such
questions  of law and  statutes of the State of  Delaware as we have  considered
necessary  or  appropriate,  and  subject  to the  assumptions,  qualifications,
limitations and exceptions set forth herein, we are of the opinion that:

                  1.       The Trust has been duly created and is validly
existing in good  standing as a business  trust under the Delaware Business
Trust Act, 12 Del. C. ss. 3801, et seq.

                  2. The Series B Capital  Securities  will represent valid and,
subject to the  qualifications  set forth in  paragraph 3 below,  fully paid and
nonassessable undivided beneficial interests in the assets of the Trust.

                  3. The Series B Capital Security Holders, as beneficial owners
of the Trust,  will be entitled  to the same  limitation  of personal  liability
extended to stockholders of private  corporations for profit organized under the
General  Corporation  Law of the State of  Delaware.  We note that the  Series B
Capital  Security  Holders may be obligated to make payments as set forth in the
Declaration of Trust.

                  We consent to the filing of this opinion  with the  Securities
and  Exchange  Commission  as an  exhibit  to  the  Registration  Statement.  In
addition,  we hereby  consent  to the use of our name under the  heading  "Legal
Matters" in the Prospectus.  In giving the foregoing consents, we do not thereby
admit that we come  within the  category  of Persons  whose  consent is required
under  Section 7 of the  Securities  Act of 1933,  as amended,  or the rules and
regulations of the Securities and Exchange Commission thereunder.

                                                     Very truly yours,


                                                     /s/ ERIC A. MAZIE
                                                         --------------
                                                         Eric A. Mazie