-----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,
 QPrXUqRzPjGAJ16acHZdK1a4/uxNSqvLSoUshFHP7XTDVhDwb5z4t7vkAESN04OQ
 L7lNFo65AYc52y2u0DoS6Q==

<SEC-DOCUMENT>0001309097-08-000006.txt : 20080527
<SEC-HEADER>0001309097-08-000006.hdr.sgml : 20080526
<ACCEPTANCE-DATETIME>20080527175536
ACCESSION NUMBER:		0001309097-08-000006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080527
FILED AS OF DATE:		20080527
DATE AS OF CHANGE:		20080527

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Macquarie Infrastructure CO LLC
		CENTRAL INDEX KEY:			0001289790
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-PETROLEUM & PETROLEUM PRODUCTS (NO BULK STATIONS) [5172]
		IRS NUMBER:				206196808
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		125 WEST 55TH STREET, 22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		212-231-1000

	MAIL ADDRESS:	
		STREET 1:		125 WEST 55TH STREET, 22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Macquarie Infrastructure Assets LLC
		DATE OF NAME CHANGE:	20040510

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Brown Norman H Jr
		CENTRAL INDEX KEY:			0001309097

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32384
		FILM NUMBER:		08861787

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		212-548-6538

	MAIL ADDRESS:	
		STREET 1:		C/O MACQUARIE INFRASTRUCTURE COMPANY LLC
		STREET 2:		600 FIFTH AVENUE, 21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10020
</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>2008-05-27</periodOfReport>

    <issuer>
        <issuerCik>0001289790</issuerCik>
        <issuerName>Macquarie Infrastructure CO LLC</issuerName>
        <issuerTradingSymbol>MIC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001309097</rptOwnerCik>
            <rptOwnerName>Brown Norman H Jr</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MACQUARIE INFRASTRUCTURE COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>125 WEST 55TH STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>LLC Interests</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4705</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19606</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Consists of restricted stock units representing an equal number of LLC Interests issuable upon vesting of such units.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Heidi Mortensen, Attorney-in-Fact</signatureName>
        <signatureDate>2008-05-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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