-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 CiJd3a55V945N1qlii9P4B0TBaqDgIwuTWqmYuRO1IypoSjMbyN5J4yEUi8RlhF3
 a1SeTVRGoBeo5qNFqYTcrw==

<SEC-DOCUMENT>0001241921-07-000095.txt : 20071205
<SEC-HEADER>0001241921-07-000095.hdr.sgml : 20071205
<ACCEPTANCE-DATETIME>20071205170556
ACCESSION NUMBER:		0001241921-07-000095
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071203
FILED AS OF DATE:		20071205
DATE AS OF CHANGE:		20071205

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MCDERMOTT INTERNATIONAL INC
		CENTRAL INDEX KEY:			0000708819
		STANDARD INDUSTRIAL CLASSIFICATION:	FABRICATED PLATE WORK (BOILER SHOPS) [3443]
		IRS NUMBER:				720593134
		STATE OF INCORPORATION:			R1
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		777 N. ELDRIDGE PARKWAY
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77079
		BUSINESS PHONE:		281-870-5000

	MAIL ADDRESS:	
		STREET 1:		777 N. ELDRIDGE PARKWAY
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77079

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WILKINSON BRUCE W
		CENTRAL INDEX KEY:			0001199548

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08430
		FILM NUMBER:		071287281

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		2818705000

	MAIL ADDRESS:	
		STREET 1:		777 N ELDRIDGE PARKWAY
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77079
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-12-03</periodOfReport>

    <issuer>
        <issuerCik>0000708819</issuerCik>
        <issuerName>MCDERMOTT INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>MDR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001199548</rptOwnerCik>
            <rptOwnerName>WILKINSON BRUCE W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MCDERMOTT INTERNATIONAL, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>777 N. ELDRIDGE PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77079</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-12-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>140000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.8333</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>855794</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-12-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>140000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>715794</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10202</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401 K Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.8333</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-12-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>140000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2012-03-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>140000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>38100</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The sale and underlying exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2007.</footnote>
        <footnote id="F2">The stock was sold in multiple transactions at the following prices: 400 @ $51.36; 400 @ $51.37; 200 @ $51.46; 100 @ $51.47; 700 @ $51.48; 800 @ $51.50; 400 @ $51.51; 600 @ $51.52; 1300 @ $51.53; 300 @ $51.54; 400 @ $51.55; 800 @ $51.56; 400 @ $51.57; 800 @ $51.70; 200 @ $51.72; 100 @ $51.74; 100 @ $51.77; 400 @ $51.84; 400 @ $51.94; 400 @ $51.96; 1200 @ $51.97; 1600 @ $51.99; 1500 @ $52.00; 400 @ $52.01; 1700 @ $52.02; 2000 @ $52.03; 2200 @ $52.04; 600 @ $52.05; 2100 @ $52.06; 1400 @ $52.08; 2900 @ $52.09; 7500 @ $52.10; 1628 @ $52.11; 1000 @ $52.12; 500 @ $52.13; 400 @ $52.14; 800 @ $52.15; 400 @ $52.17; 1600 @ $52.18; 400 @ $52.19; 400 @ $52.20; 800 @ $52.21; 400 @ $52.22; 900 @ $52.23; 100 @ $52.24; 1300 @ $52.25; 300 @ $52.26; 600 @ $52.27; 1300 @ $52.28; 2000 @ $52.29; 1300 @ $52.30; 1300 @ $52.31; 500 @ $52.32; 1800 @ $52.33; 700 @ $52.34; 500 @ $52.35; 1500 @ $52.36; 1000 @ $52.37; 1100 @ $52.38; 1000 @ $52.39; continued on footnote no. 3</footnote>
        <footnote id="F3">continued from footnote no. 2; 1200 @ $52.40; 600 @ $52.41; 700 @ $52.42; 1300 @ $52.43; 2000 @ $52.44; 1500 @ $52.45; 2200 @ $52.46; 400 @ $52.47; 800 @ $52.48; 200 @ $52.49; 1500 @ $52.50; 800 @ $52.51; 500 @ $52.52; 1300 @ $52.53; 300 @ $52.54; 800 @ $52.55; 2100 @ $52.56; 1000 @ $52.57; 1500 @ $52.58; 2000 @ $52.59; 1800 @ $52.60; 300 @ $52.61; 400 @ $52.62; 800 @ $52.63; 1500 @ $52.64; 100 @ $52.65; 2200 @ $52.66; 900 @ $52.69; 1400 @ $52.70; 1400 @ $52.71; 1600 @ $52.72; 800 @ $52.75; 1200 @ $52.78; 700 @ $52.79; 2100 @ $52.80; 600  @ $52.81; 1800 @ $52.82; 2500 @ $52.83; 1378 @ $52.84; 800 @ $52.85; 900 @ $52.86; 1000 @ $52.87; 300 @ $52.88; 800 @ $52.89; 400 @ $52.90; 400 @ $52.91; 700 @ $52.92; 300 @ $52.94; 200 @ $52.95; 1100 @ $52.96; 1100 @ $52.97; 770 @ $52.98; 1600 @ $52.99; 1030 @ $53.00; 1600 @ $53.01; 300 @ $53.02; 494 @ $53.03; 1200 @ $53.04; 2800 @ $53.06; 1500 @ $53.07; 1300 @ $53.08; 1000 @ $53.09; continued on footnote no. 4</footnote>
        <footnote id="F4">continued from footnote no. 3; 400 @ $53.14; 300 @ $53.15; 1100 @ $53.18; 400 @ $53.23; 1200 @ $53.24; 400 @ $53.25; 300 @ $53.26; 400 @ $53.29; 600 @ $53.30; 200 @ $53.31; 800 @ $53.32; 700 @ $53.33; 600 @ $53.34; 1300 @ $53.36; 800 @ $53.37; 1900 @ $53.39; 600 @ $53.42 and 400 @ $53.46.</footnote>
        <footnote id="F5">Based upon units held in 401K Plan and the fair market value of Common Stock as of December 3, 2007.</footnote>
        <footnote id="F6">This option vested in three equal installments on March 6, 2003, 2004 and 2005.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Liane K. Hinrichs, by power of attorney</signatureName>
        <signatureDate>2007-12-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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