-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 ITk6/cP8zjU/pRRawZGd8cYI/qJkv39He3BfGlCPWeZ9Hvjx4NOvNRv/1prRBji4
 7ZEMThlwzUrTShqXwfYMNA==

<SEC-DOCUMENT>0001309619-06-000002.txt : 20060104
<SEC-HEADER>0001309619-06-000002.hdr.sgml : 20060104
<ACCEPTANCE-DATETIME>20060104144511
ACCESSION NUMBER:		0001309619-06-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20051230
FILED AS OF DATE:		20060104
DATE AS OF CHANGE:		20060104

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Klash Ronald M
		CENTRAL INDEX KEY:			0001309619

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31703
		FILM NUMBER:		06506652

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		301-939-7000

	MAIL ADDRESS:	
		STREET 1:		C/O ESSEX CORPORATION
		STREET 2:		9150 GUILFORD ROAD
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21046

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ESSEX CORP
		CENTRAL INDEX KEY:			0000355199
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ENGINEERING SERVICES [8711]
		IRS NUMBER:				540846569
		STATE OF INCORPORATION:			VA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6708 ALEXANDER BELL DRIVE
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21046
		BUSINESS PHONE:		3019397000

	MAIL ADDRESS:	
		STREET 1:		6708 ALEXANDER BELL DRIVE
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21046

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ESSEX CORPORATION
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ron123005form4_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-12-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000355199</issuerCik>
        <issuerName>ESSEX CORP</issuerName>
        <issuerTradingSymbol>KEYW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001309619</rptOwnerCik>
            <rptOwnerName>Klash Ronald M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ESSEX CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>9150 GUILFORD ROAD</rptOwnerStreet2>
            <rptOwnerCity>COLUMBIA</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21046</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President, Controller</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>16.94</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-12-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2005-12-30</value>
            </exerciseDate>
            <expirationDate>
                <value>2012-12-29</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>Ronald M. Klash</signatureName>
        <signatureDate>2006-01-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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