    <SEC-DOCUMENT>0001193125-15-070365-index.html : 20150228
    <SEC-HEADER>0001193125-15-070365.hdr.sgml : 20150227
    <ACCEPTANCE-DATETIME>20150227172603
    ACCESSION NUMBER:		0001193125-15-070365
    CONFORMED SUBMISSION TYPE:	N-CSR
    PUBLIC DOCUMENT COUNT:		20
    CONFORMED PERIOD OF REPORT:	20141231
    FILED AS OF DATE:		20150227
    DATE AS OF CHANGE:		20150227
    EFFECTIVENESS DATE:		20150227

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			BlackRock Utility & Infrastructure Trust
    		CENTRAL INDEX KEY:			0001528988
    		IRS NUMBER:				000000000
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1031

    	FILING VALUES:
    		FORM TYPE:		N-CSR
    		SEC ACT:		1940 Act
    		SEC FILE NUMBER:	811-22606
    		FILM NUMBER:		15660798

    	BUSINESS ADDRESS:
    		STREET 1:		55 EAST 52ND STREET
    		CITY:			NEW YORK
    		STATE:			NY
    		ZIP:			10055
    		BUSINESS PHONE:		(800) 882-0052

    	MAIL ADDRESS:
    		STREET 1:		55 EAST 52ND STREET
    		CITY:			NEW YORK
    		STATE:			NY
    		ZIP:			10055
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>N-CSR
    <SEQUENCE>1
    <FILENAME>d851753dncsr.htm
    <DESCRIPTION>BLACKROCK UTILITY & INFRASTRUCTURE TRUST
    <TEXT>
    Document 1 - file: d851753dncsr.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.CERT
    <SEQUENCE>2
    <FILENAME>d851753dex99cert.htm
    <DESCRIPTION>CERTIFICATIONS PURSUANT TO SECTION 302
    <TEXT>
    Document 2 - file: d851753dex99cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.906CERT
    <SEQUENCE>3
    <FILENAME>d851753dex99906cert.htm
    <DESCRIPTION>CERTIFICATIONS PURSUANT TO SECTION 906
    <TEXT>
    Document 3 - file: d851753dex99906cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.PROXYPOL
    <SEQUENCE>4
    <FILENAME>d851753dex99proxypol.htm
    <DESCRIPTION>PROXY VOTING POLICY
    <TEXT>
    Document 4 - file: d851753dex99proxypol.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.12(C)
    <SEQUENCE>5
    <FILENAME>d851753dex9912c.htm
    <DESCRIPTION>19(A) NOTICES
    <TEXT>
    Document 5 - file: d851753dex9912c.htm

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    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>g851271leaf.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: g851271leaf.jpg

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    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>g851271proxypol_logo.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: g851271proxypol_logo.jpg

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    <DOCUMENT>
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    <SEQUENCE>8
    <FILENAME>g851271proxypol_p1a.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: g851271proxypol_p1a.jpg

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    <SEQUENCE>9
    <FILENAME>g851271proxypol_p1b.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: g851271proxypol_p1b.jpg

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    <SEQUENCE>10
    <FILENAME>g851271tx_pg04a.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: g851271tx_pg04a.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>g851271tx_pg04b.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: g851271tx_pg04b.jpg

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    <SEQUENCE>12
    <FILENAME>g851271tx_pg07.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: g851271tx_pg07.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>g851271tx_pg09.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: g851271tx_pg09.jpg

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    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>g851271tx_pg11.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: g851271tx_pg11.jpg

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    <SEQUENCE>15
    <FILENAME>g851271tx_pg13.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: g851271tx_pg13.jpg

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    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>g851271tx_pg15.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: g851271tx_pg15.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>g851271tx_pg17.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 17 - file: g851271tx_pg17.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>g851271tx_pg19.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 18 - file: g851271tx_pg19.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>g851271tx_pg21.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 19 - file: g851271tx_pg21.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>g851271tx_pg23.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 20 - file: g851271tx_pg23.jpg

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    </SEC-DOCUMENT>