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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 VKhyMs0yDx4eg87nNRTncGbfxiAFKoQlM3y+a7zT5u/c797i6L2R0wN15n9t9vRG
 ddrdTigY21+H86CCsMPJ/w==

<SEC-DOCUMENT>0001009121-06-000014.txt : 20061215
<SEC-HEADER>0001009121-06-000014.hdr.sgml : 20061215
<ACCEPTANCE-DATETIME>20061215162458
ACCESSION NUMBER:		0001009121-06-000014
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20061214
FILED AS OF DATE:		20061215
DATE AS OF CHANGE:		20061215

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ROYCE MICRO CAP TRUST INC /MD/
		CENTRAL INDEX KEY:			0000912147
		IRS NUMBER:				133739778
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		C/O ROYCE & ASSOCIATES, INC.
		STREET 2:		1414 AVE OF THE AMERICAS
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		2124084587

	MAIL ADDRESS:	
		STREET 1:		ROYCE MICRO-CAP TRUST, INC.
		STREET 2:		1414 AVE OF THE AMERICAS
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ROYCE OTC MICRO CAP FUND INC
		DATE OF NAME CHANGE:	19930917

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ROYCE CHARLES M
		CENTRAL INDEX KEY:			0001009121
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-08030
		FILM NUMBER:		061280728

	BUSINESS ADDRESS:	
		STREET 1:		C/O ROYCE & ASSOCIATES, LLC
		STREET 2:		1414 AVE OF THE AMERICAS
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		2124861445

	MAIL ADDRESS:	
		STREET 1:		C/O ROYCE & ASSOCIATES, LLC
		STREET 2:		1414 AVENUE OF THE AMERICAS
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-12-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000912147</issuerCik>
        <issuerName>ROYCE MICRO CAP TRUST INC /MD/</issuerName>
        <issuerTradingSymbol>RMT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001009121</rptOwnerCik>
            <rptOwnerName>ROYCE CHARLES M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ROYCE &amp; ASSOCIATES, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>1414 AVENUE OF THE AMERICAS</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle>President</officerTitle>
            <otherText>President - Investment Adviser</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-12-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>36500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.5292</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>814312</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-12-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>13500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.5327</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>800812</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>282148</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Family Investment Entity</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Shares held by a family investment entity of which the reporting person is the sole managing member and in which the reporting person has a substantial pecuniary interest (which may vary from time to time).  The reporting person disclaims beneficial ownership of such 282,148 shares owned by the family investment entity in which he has no pecuniary interest.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Dani Eng, Attorney-in-Fact</signatureName>
        <signatureDate>2006-12-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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