<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-07-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000318300</issuerCik>
        <issuerName>PEOPLES BANCORP INC</issuerName>
        <issuerTradingSymbol>PEBO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001021202</rptOwnerCik>
            <rptOwnerName>MAIDEN REX E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeSecurity>
        <securityTitle>
            <value>Deferred Compensation</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>0</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-07-01</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionAmounts>
            <transactionShares>
                <value>7</value>
            </transactionShares>
            <transactionValue>
                <value>25.26</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>1988-08-08</value>
                <footnoteId id="F1"/>
        </exerciseDate>
        <expirationDate>
            <value>1988-08-08</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>7</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>1204</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">Exercise date shown not actual exercise date. Shares are only payable subsequent to termination of service pursuant to the terms and conditions of the Peoples Bancorp Inc. Deferred Compensation Plan for Directors of Peoples Bancorp Inc. and Subsidiaries. </footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Gary L. Kriechbaum  For: Rex E. Maiden</signatureName>
        <signatureDate>2003-07-10</signatureDate>
    </ownerSignature>

</ownershipDocument>

