-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 dLgo5VunqIVXQhYprzfKjA==

<SEC-DOCUMENT>0001081250-03-000003.txt : 20030827
<SEC-HEADER>0001081250-03-000003.hdr.sgml : 20030827
<ACCEPTANCE-DATETIME>20030827150316
ACCESSION NUMBER:		0001081250-03-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030825
FILED AS OF DATE:		20030827

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BRONSON STEVEN N
		CENTRAL INDEX KEY:			0001000383
		STATE OF INCORPORATION:			FL
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-16335
		FILM NUMBER:		03868424

	BUSINESS ADDRESS:	
		STREET 1:		201 SOUTH BISCAYNE BLVD
		STREET 2:		STE 2950
		CITY:			MIAMI
		STATE:			FL
		ZIP:			33131
		BUSINESS PHONE:		305368501

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RIDGEFIELD ACQUISITION CORP
		CENTRAL INDEX KEY:			0000812152
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER PERIPHERAL EQUIPMENT, NEC [3577]
		IRS NUMBER:				840922701
		STATE OF INCORPORATION:			CO
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		900 THIRD AVE
		STREET 2:		SUITE 201
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		3033680401

	MAIL ADDRESS:	
		STREET 1:		900 THIRD AVE
		STREET 2:		SUITE 201
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BIO MEDICAL AUTOMATION INC
		DATE OF NAME CHANGE:	19990323

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OZO DIVERSIFIED AUTOMATION INC /CO/
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-08-25</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000812152</issuerCik>
        <issuerName>RIDGEFIELD ACQUISITION CORP</issuerName>
        <issuerTradingSymbol>RDGA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001000383</rptOwnerCik>
            <rptOwnerName>BRONSON STEVEN N</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-08-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>27413</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.94</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>584160</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Options</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.125</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-06-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>90000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.125</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2000-02-20</value>
            </exerciseDate>
            <expirationDate>
                <value>2003-06-24</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>90000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>150000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">This amount does not include 33,500 shares of the Issuer's common stock owned by Mr. Bronson's spouse.  Mr. Bronson expressly disclaims beneficial ownership of the shares of common stock owned by his spouse.</footnote>
        <footnote id="F2">Expiration of options</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>Steven N. Bronson</signatureName>
        <signatureDate>2003-08-27</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----