<SUBMISSION>
<ACCESSION-NUMBER>0001308126-05-000006
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20050324
<FILING-DATE>20050325
<DATE-OF-FILING-DATE-CHANGE>20050325
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>MARLOW JOHN K
<CIK>0001252748
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-23976
<FILM-NUMBER>05704916
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>112 W KING STREET
<CITY>STRASBURG
<STATE>VA
<ZIP>22657
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>FIRST NATIONAL CORP /VA/
<CIK>0000719402
<ASSIGNED-SIC>6022
<IRS-NUMBER>541231965
<STATE-OF-INCORPORATION>VA
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>100 WEST KING STREET
<CITY>STRASBURG
<STATE>VA
<ZIP>22657
<PHONE>7034659121
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>100 WEST KING STREET
<CITY>STRASBURG
<STATE>VA
<ZIP>22657
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-03-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000719402</issuerCik>
        <issuerName>FIRST NATIONAL CORP /VA/</issuerName>
        <issuerTradingSymbol>FXNC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001252748</rptOwnerCik>
            <rptOwnerName>MARLOW JOHN K</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>112 W KING STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>STRASBURG</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22657</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-03-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>200</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>45.5</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2200</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Marlow Investment LLC</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">300 Additional owned indirectly
2800 Additional owned directly</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Nancy T Fitchett by power of attorney    DIRECTOR</signatureName>
        <signatureDate>2005-03-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
