PAGE 1
000 A000000 02/29/2004
000 C000000 0001181187
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 A
001 A000000 BLACKROCK INSURED MUNICIPAL INCOME TRUST
001 B000000 811-21178
001 C000000 3027972162
002 A000000 100 BELLEVUE PARKWAY
002 B000000 WILMINGTON
002 C000000 DE
002 D010000 19809
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
007 C010100 1
007 C010200 2
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A000001 BLACKROCK ADVISORS, INC.
008 B000001 A
008 C000001 801-47710
008 D010001 WILMINGTON
008 D020001 DE
008 D030001 19809
008 A000002 BLACKROCK FINANCIAL MANAGEMENT,INC.
008 B000002 S
008 C000002 801-48433
008 D010002 NEW YORK
008 D020002 NY
008 D030002 10022
012 A000001 EQUISERVE TRUST COMPANY, NA
012 B000001 85-11340
012 C010001 CANTON
012 C020001 MA
012 C030001 02021
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 BOSTON
PAGE 2
013 B020001 MA
013 B030001 02116
014 A000001 BLACKROCK INVESTMENTS, INC.
014 B000001 8-048436
014 A000002 NORTHERN FUND DISTRIBUTORS, LLC
014 B000002 8-051242
014 A000003 PNC CAPITAL MARKETS, INC.
014 B000003 8-032493
014 A000004 J.J.B. HILLIARD W.L. LYONS, INC.
014 B000004 8-033133
014 A000005 PFPC DISTRIBUTORS, INC.
014 B000005 8-045467
014 A000006 OFFIT FUNDS DISTRIBUTOR, INC.
014 B000006 8-046960
014 A000007 ABN AMRO DISTRIBUTION SERVICES (USA), INC.
014 B000007 8-052396
014 A000008 BLACKROCK DISTRIBUTORS, INC.
014 B000008 8-048775
015 A000001 STATESTREET BANK AND TRUST COMPANY
015 B000001 C
015 C010001 BOSTON
015 C020001 MA
015 C030001 02110
015 E010001 X
015 A000002 PRUDENTIAL SECURITIES, INC.
015 B000002 C
015 C010002 SPRING LAKE
015 C020002 NJ
015 C030002 07762
015 C040002 1443
015 E020002 X
018 000000 Y
019 A000000 Y
019 B000000 49
019 C000000 BLACKROCKF
020 A000001 PRUDENTIAL SECURITIES, INC.
020 B000001 22-2347336
020 C000001 0
020 C000002 0
020 C000003 0
020 C000004 0
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 0
022 A000001 CITIGROUP GLOBAL MARKETS INC.
022 B000001 11-2418191
022 C000001 67403
PAGE 3
022 D000001 88475
022 A000002 STATE STREET BANK
022 B000002 04-1867445
022 C000002 98250
022 D000002 86600
022 A000003 MORGAN STANLEY
022 B000003 13-2655998
022 C000003 38162
022 D000003 14423
022 A000004 CHASE SECURITIES INC.
022 B000004 13-3379014
022 C000004 19346
022 D000004 0
022 A000005 MERRILL LYNCH
022 B000005 13-5674085
022 C000005 8256
022 D000005 7814
022 A000006 GOLDMAN SACHS
022 B000006 13-5108880
022 C000006 0
022 D000006 14961
022 A000007 EDWARDS A G SONS
022 B000007 43-0895447
022 C000007 8145
022 D000007 8634
022 A000008 UBS PAINE WEBBER
022 B000008 13-3873456
022 C000008 8490
022 D000008 10802
022 A000009 BANC OF AMERICA SECURITIES LLC
022 B000009 56-2058405
022 C000009 8000
022 D000009 7590
022 A000010 BEAR STEARNS
022 B000010 13-3299429
022 C000010 0
022 D000010 7715
023 C000000 272890
023 D000000 256320
024 000000 N
025 D000001 0
025 D000002 0
025 D000003 0
025 D000004 0
025 D000005 0
025 D000006 0
025 D000007 0
025 D000008 0
026 A000000 N
026 B000000 N
026 C000000 N
PAGE 4
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 N
028 A010000 0
028 A020000 0
028 A030000 0
028 A040000 0
028 B010000 0
028 B020000 0
028 B030000 0
028 B040000 0
028 C010000 0
028 C020000 0
028 C030000 0
028 C040000 0
028 D010000 0
028 D020000 0
028 D030000 0
028 D040000 0
028 E010000 0
028 E020000 0
028 E030000 0
028 E040000 0
028 F010000 0
028 F020000 0
028 F030000 0
028 F040000 0
028 G010000 0
028 G020000 0
028 G030000 0
028 G040000 0
028 H000000 0
030 A000000 0
030 B000000 0.00
030 C000000 0.00
031 A000000 0
031 B000000 0
032 000000 0
033 000000 0
035 000000 0
036 B000000 0
038 000000 0
042 A000000 0
042 B000000 0
042 C000000 0
042 D000000 0
042 E000000 0
PAGE 5
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 0
044 000000 0
045 000000 Y
046 000000 N
047 000000 Y
048 000000 0.550
048 A010000 0
048 A020000 0.000
048 B010000 0
048 B020000 0.000
048 C010000 0
048 C020000 0.000
048 D010000 0
048 D020000 0.000
048 E010000 0
048 E020000 0.000
048 F010000 0
048 F020000 0.000
048 G010000 0
048 G020000 0.000
048 H010000 0
048 H020000 0.000
048 I010000 0
048 I020000 0.000
048 J010000 0
048 J020000 0.000
048 K010000 0
048 K020000 0.000
049 000000 N
050 000000 N
051 000000 N
052 000000 N
053 A000000 Y
053 B000000 N
053 C000000 N
054 A000000 Y
054 B000000 Y
054 C000000 N
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 Y
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 N
054 M000000 Y
PAGE 6
054 N000000 N
054 O000000 N
055 A000000 N
055 B000000 N
056 000000 Y
057 000000 N
058 A000000 N
059 000000 Y
060 A000000 Y
060 B000000 Y
061 000000 0
062 A000000 Y
062 B000000 0.0
062 C000000 0.0
062 D000000 0.0
062 E000000 0.0
062 F000000 0.0
062 G000000 0.0
062 H000000 0.0
062 I000000 0.0
062 J000000 0.0
062 K000000 0.0
062 L000000 0.0
062 M000000 0.0
062 N000000 0.0
062 O000000 153.2
062 P000000 0.0
062 Q000000 0.0
062 R000000 3.0
063 A000000 0
063 B000000 26.1
064 A000000 Y
064 B000000 N
066 A000000 N
067 000000 N
068 A000000 N
068 B000000 N
069 000000 N
070 A010000 Y
070 A020000 N
070 B010000 N
070 B020000 N
070 C010000 Y
070 C020000 N
070 D010000 N
070 D020000 N
070 E010000 Y
070 E020000 N
070 F010000 N
070 F020000 N
070 G010000 Y
PAGE 7
070 G020000 N
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 N
070 K010000 Y
070 K020000 Y
070 L010000 N
070 L020000 N
070 M010000 N
070 M020000 N
070 N010000 Y
070 N020000 N
070 O010000 Y
070 O020000 Y
070 P010000 Y
070 P020000 Y
070 Q010000 N
070 Q020000 N
070 R010000 Y
070 R020000 N
071 A000000 147205
071 B000000 140895
071 C000000 597992
071 D000000 24
072 A000000 6
072 B000000 15412
072 C000000 0
072 D000000 0
072 E000000 0
072 F000000 1064
072 G000000 0
072 H000000 0
072 I000000 7
072 J000000 48
072 K000000 0
072 L000000 33
072 M000000 27
072 N000000 16
072 O000000 0
072 P000000 0
072 Q000000 0
072 R000000 22
072 S000000 20
072 T000000 0
072 U000000 0
072 V000000 0
072 W000000 342
072 X000000 1579
PAGE 8
072 Y000000 0
072 Z000000 13833
072AA000000 0
072BB000000 4874
072CC010000 47918
072CC020000 0
072DD010000 12258
072DD020000 0
072EE000000 0
073 A010000 0.4687
073 A020000 0.0000
073 B000000 0.0000
073 C000000 0.0000
074 A000000 504
074 B000000 0
074 C000000 0
074 D000000 625322
074 E000000 0
074 F000000 0
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 0
074 K000000 0
074 L000000 6441
074 M000000 51
074 N000000 632318
074 O000000 0
074 P000000 171
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 2786
074 S000000 229007
074 T000000 400354
074 U010000 26149
074 U020000 0
074 V010000 15.31
074 V020000 0.00
074 W000000 0.0000
074 X000000 100
074 Y000000 0
075 A000000 0
075 B000000 382289
076 000000 14.70
077 A000000 N
078 000000 N
080 C000000 0
081 B000000 0
082 B000000 0
PAGE 9
083 B000000 0
084 B000000 0
086 A010000 24
086 A020000 323
086 B010000 0
086 B020000 0
086 C010000 0
086 C020000 0
086 D010000 0
086 D020000 0
086 E010000 0
086 E020000 0
086 F010000 0
086 F020000 0
087 A010000 COMMON
087 A020000 092479104
087 A030000 BYM
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 Y
SIGNATURE HENRY GABBAY
TITLE TREASURER