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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-01-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001481832</issuerCik>
        <issuerName>PREFERRED APARTMENT COMMUNITIES INC</issuerName>
        <issuerTradingSymbol>APTS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001232172</rptOwnerCik>
            <rptOwnerName>MURPHY JOEL T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3284 NORTHSIDE PARKWAY NW</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 150</rptOwnerStreet2>
            <rptOwnerCity>ATLANTA</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>30327</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO-New Market Properties, LLC</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class A Units</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-01-03</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8118</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8118</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>50000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents Class A Units (&quot;Class A Unit&quot;) of Preferred Apartment Communities Operating Partnership, L.P. (the &quot;Operating Partnership&quot;), of which Preferred Apartment Communities, Inc. (the &quot;Company&quot;) is the general partner.  On January 4, 2016, the reporting person was awarded a maximum of 24,353 Class B Units of the Operating Partnership (&quot;Class B Units&quot;) issued in lieu of any reimbursement for annual cash compensation for 2016, 2017 and 2018, subject to certain performance conditions.  When earned and vested, each Class B Unit is converted into a Class A Unit.  Each Class A Unit may be exchanged for one share of the Company's common stock, or cash, as selected by the Company.  Class A Units do not expire.</footnote>
        <footnote id="F2">As of January 3, 2017, the Compensation Committee of the Board of Directors of the Company determined that the extent to which the performance measures had been achieved during the performance period resulted in 100%, or 24,353 of the Class B Units becoming earned Class B Units.  One-third of the earned Class B Units, or 8,118 Class B Units, fully vested on January 3, 2017 and were converted into Class A Units on that date.  The remaining 16,235 unvested Class B Units will vest approximately equally on January 2, 2018 and January 2, 2019 and will convert to Class A Units on those dates.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jeffrey R. Sprain, attorney-in-fact</signatureName>
        <signatureDate>2017-01-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
