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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 2wjH4OpLm7GUWhwVxBU1jw==

<SEC-DOCUMENT>0000004977-08-000057.txt : 20080813
<SEC-HEADER>0000004977-08-000057.hdr.sgml : 20080813
<ACCEPTANCE-DATETIME>20080813133420
ACCESSION NUMBER:		0000004977-08-000057
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080812
FILED AS OF DATE:		20080813
DATE AS OF CHANGE:		20080813

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AFLAC INC
		CENTRAL INDEX KEY:			0000004977
		STANDARD INDUSTRIAL CLASSIFICATION:	ACCIDENT & HEALTH INSURANCE [6321]
		IRS NUMBER:				581167100
		STATE OF INCORPORATION:			GA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1932 WYNNTON RD
		CITY:			COLUMBUS
		STATE:			GA
		ZIP:			31999
		BUSINESS PHONE:		7063233431

	MAIL ADDRESS:	
		STREET 1:		1932 WYNNTON ROAD
		CITY:			COLUMBUS
		STATE:			GA
		ZIP:			31999

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AMERICAN FAMILY CORP
		DATE OF NAME CHANGE:	19920306

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PURDOM E STEPHEN
		CENTRAL INDEX KEY:			0001075304

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07434
		FILM NUMBER:		081012581

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		7065963499

	MAIL ADDRESS:	
		STREET 1:		1932 WYNNTON ROAD
		CITY:			COLUMBUS
		STATE:			GA
		ZIP:			31999
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-08-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000004977</issuerCik>
        <issuerName>AFLAC INC</issuerName>
        <issuerTradingSymbol>AFL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001075304</rptOwnerCik>
            <rptOwnerName>PURDOM E STEPHEN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1932 WYNNTON ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>COLUMBUS</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>31999</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Director Stock Option</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>55.72</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-08-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>55.72</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-08-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Granted under the 2004 Aflac Incorporated Long-Term Incentive Plan.</footnote>
        <footnote id="F2">The option becomes exercisable in four equal annual installments on August 12, 2009, 2010, 2011 and 2012.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Patricia A. Bell as Power of Attorney</signatureName>
        <signatureDate>2008-08-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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