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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-12-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000739421</issuerCik>
        <issuerName>CITIZENS FINANCIAL SERVICES INC</issuerName>
        <issuerTradingSymbol>CZFS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001294689</rptOwnerCik>
            <rptOwnerName>Mosso Robert B Mr</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12 MORRIS LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WELLSBORO</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>16901</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SENIOR VICE PRESIDENT</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON CLASS</value>
            </securityTitle>
            <transactionDate>
                <value>2015-12-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>50</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>740.529</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>STOCK AWARDS GRANTED PURSUANT TO THE CITIZENS FINANCIAL SERVICES, INC. 2006 RESTRICTED STOCK PLAN VEST IN THREE EQUAL ANNUAL INSTALLMENTS COMMENCNG ON DECEMBER 15, 2016.</remarks>

    <ownerSignature>
        <signatureName>GINA MARIE BOOR FOR ROBERT B. MOSSO UNDER POWER OF ATTORNEY DATED 06/17/2004</signatureName>
        <signatureDate>2015-12-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0306
4
2015-12-15
0
0000739421
CITIZENS FINANCIAL SERVICES INC
CZFS
0001294689
Mosso Robert B Mr
12 MORRIS LANE
WELLSBORO
PA
16901
0
1
0
0
SENIOR VICE PRESIDENT
COMMON CLASS
2015-12-15
4
A
0
50
0
A
740.529
D
STOCK AWARDS GRANTED PURSUANT TO THE CITIZENS FINANCIAL SERVICES, INC. 2006 RESTRICTED STOCK PLAN VEST IN THREE EQUAL ANNUAL INSTALLMENTS COMMENCNG ON DECEMBER 15, 2016.
GINA MARIE BOOR FOR ROBERT B. MOSSO UNDER POWER OF ATTORNEY DATED 06/17/2004
2015-12-17