-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 D8nBmhwoaRlFU+4XcRndsuayRL6pMwwVbrNw+awgUcoUzT9vqTzBqvWIs0B+iMBA
 hYrfpa+r5RrVUXLMuoTSaQ==

<SEC-DOCUMENT>0001042046-03-000142.txt : 20030723
<SEC-HEADER>0001042046-03-000142.hdr.sgml : 20030723
<ACCEPTANCE-DATETIME>20030723105138
ACCESSION NUMBER:		0001042046-03-000142
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030723
FILED AS OF DATE:		20030723

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RUNK FRED J
		CENTRAL INDEX KEY:			0001185846

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13653
		FILM NUMBER:		03797597

	BUSINESS ADDRESS:	
		STREET 1:		ONE EAST FOURTH STREET
		STREET 2:		SUITE 919
		CITY:			CINCINNATI
		STATE:			OH
		ZIP:			45202
		BUSINESS PHONE:		5135792540

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AMERICAN FINANCIAL GROUP INC
		CENTRAL INDEX KEY:			0001042046
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		IRS NUMBER:				311544320
		STATE OF INCORPORATION:			OH
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE EAST FOURTH STREET
		STREET 2:		SUITE 919
		CITY:			CINCINNATI
		STATE:			OH
		ZIP:			45202
		BUSINESS PHONE:		5135792121

	MAIL ADDRESS:	
		STREET 1:		ONE EAST FOURTH STREET
		STREET 2:		SUITE 919
		CITY:			CINCINNATI
		STATE:			OH
		ZIP:			45202

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AMERICAN FINANCIAL GROUP HOLDINGS INC
		DATE OF NAME CHANGE:	19970709
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-07-23</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001042046</issuerCik>
        <issuerName>AMERICAN FINANCIAL GROUP INC</issuerName>
        <issuerTradingSymbol>AFG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001185846</rptOwnerCik>
            <rptOwnerName>RUNK FRED J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. Vice President &amp; Treasurer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-23</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>P</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>71</value>
            </transactionShares>
            <transactionValue>
                <value>22.58</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>241888</value>
                <footnoteId id="F1"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <footnotes>
        <footnote id="F1">Excludes additional Indirect holdings in an ESPP Account - 6,388.55 (as of 12/31/2002)
Excludes additional Indirect holdings in a DRIP Account - 1,356 (as of 12/31/2002)</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Fred J. Runk</signatureName>
        <signatureDate>2003-07-23</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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