PAGE 1
000 A000000 04/30/2010
000 C000000 0001314966
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 HEALTH SCIENCES TRUST
001 B000000 811-21702
001 C000000 8888252257
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
008 A000001 BLACKROCK ADVISORS, LLC
008 B000001 A
008 C000001 801-47710
008 D010001 WILMINGTON
008 D020001 DE
008 D030001 19809
012 A000001 BNY MELLON SHAREOWNER SERVICES
012 B000001 85-0000000
012 C010001 JERSEY CITY
012 C020001 NJ
012 C030001 07310
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 NEW YORK
013 B020001 NY
013 B030001 10281
014 A000001 BLACKROCK INVESTMENTS, INC.
014 B000001 8-048436
014 A000002 PNC CAPITAL MARKETS, INC.
014 B000002 8-032493
014 A000003 PFPC DISTRIBUTORS, INC.
014 B000003 8-045467
014 A000004 MGI FUNDS DISTRIBUTOR, INC.
014 B000004 8-046960
014 A000005 BB&T AM Distributors, Inc.
014 B000005 8-052396
014 A000006 Fairholme Distributors, Inc.
014 B000006 8-00000
014 A000007 PNC INVESTMENTS LLC
PAGE 2
014 B000007 8-066195
014 A000008 Highmark Funds Distributors, Inc.
014 B000008 8-00000
014 A000009 Harris Williams LLC
014 B000009 8-53380
014 A000010 BLACKROCK CAPITAL MARKETS, LLC
014 B000010 8-67827
014 A000011 Red Capital Markets, Inc.
014 B000011 8-31175
014 A000012 BLACKROCK EXECUTION SERVICES
014 B000012 8-48719
014 A000013 BLACKROCK FUND DISTRIBUTION CO.
014 B000013 8-67795
015 A000001 THE BANK OF NEW YORK MELLON
015 B000001 C
015 C010001 NEW YORK
015 C020001 NY
015 C030001 10286
015 E010001 X
018 000000 Y
019 A000000 Y
019 B000000 279
019 C000000 BLKRKADVSR
020 A000001 CREDIT SUISSE FIRST BOSTON
020 B000001 13-5659485
020 C000001 77
020 A000002 MORGAN STANLEY
020 B000002 13-2655998
020 C000002 48
020 A000003 CITIGROUP
020 B000003 11-2418191
020 C000003 34
020 A000004 GOLDMAN SACHS & CO.
020 B000004 13-5108880
020 C000004 27
020 A000005 DEUTSCHE BANK SECURITIES, INC.
020 B000005 13-2473088
020 C000005 26
020 A000006 MERRILL LYNCH
020 B000006 13-5674085
020 C000006 24
020 A000007 Sanford C. Bernstein & Co., LLC
020 C000007 23
020 A000008 UBS SECURITIES
020 B000008 13-2932996
020 C000008 22
020 A000009 LIQUIDNET
020 B000009 13-4095933
020 C000009 18
020 A000010 BARCLAYS CAPITAL INC.
020 B000010 06-1031656
PAGE 3
020 C000010 17
021 000000 456
022 A000001 BANK OF NEW YORK MELLON
022 B000001 13-5160382
022 C000001 130865
022 D000001 127864
022 A000002 UBS SECURITIES
022 B000002 13-2932996
022 C000002 510
022 D000002 7328
022 A000003 CREDIT SUISSE FIRST BOSTON
022 B000003 13-5659485
022 C000003 1310
022 D000003 6446
022 A000004 MORGAN STANLEY
022 B000004 13-2655998
022 C000004 861
022 D000004 5436
022 A000005 CITIGROUP
022 B000005 11-2418191
022 C000005 2511
022 D000005 3292
022 A000006 BANC OF AMERICA SECURITIES LLC
022 B000006 76-0385312
022 C000006 32
022 D000006 1590
022 A000007 BARCLAYS CAPITAL INC.
022 B000007 06-1031656
022 C000007 1421
022 D000007 0
022 A000008 GOLDMAN SACHS & CO.
022 B000008 13-5108880
022 C000008 93
022 D000008 814
022 A000009 JP MORGAN CHASE BANK
022 B000009 13-2624428
022 C000009 404
022 D000009 304
022 A000010 BNP PARIBAS
022 C000010 58
022 D000010 636
023 C000000 138514
023 D000000 154564
024 000000 N
026 A000000 N
026 B000000 N
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
PAGE 4
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
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 0
PAGE 5
044 000000 0
045 000000 Y
046 000000 N
047 000000 Y
048 000000 1.000
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 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
054 N000000 N
054 O000000 N
055 A000000 N
055 B000000 N
056 000000 Y
057 000000 N
PAGE 6
058 A000000 N
059 000000 Y
060 A000000 N
060 B000000 N
061 000000 0
062 A000000 N
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 0.0
062 P000000 0.0
062 Q000000 0.0
062 R000000 0.0
063 A000000 0
063 B000000 0.0
066 A000000 Y
066 B000000 N
066 C000000 N
066 D000000 N
066 E000000 Y
066 F000000 N
066 G000000 N
067 000000 N
068 A000000 N
068 B000000 N
069 000000 N
070 A010000 Y
070 A020000 N
070 B010000 Y
070 B020000 Y
070 C010000 Y
070 C020000 N
070 D010000 Y
070 D020000 N
070 E010000 Y
070 E020000 N
070 F010000 Y
070 F020000 N
070 G010000 Y
070 G020000 N
070 H010000 Y
PAGE 7
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 N
070 K010000 Y
070 K020000 Y
070 L010000 Y
070 L020000 Y
070 M010000 Y
070 M020000 N
070 N010000 Y
070 N020000 Y
070 O010000 Y
070 O020000 N
070 P010000 Y
070 P020000 Y
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 267331
071 B000000 262745
071 C000000 198591
071 D000000 132
072 A000000 6
072 B000000 5
072 C000000 1614
072 D000000 0
072 E000000 0
072 F000000 1041
072 G000000 0
072 H000000 0
072 I000000 6
072 J000000 53
072 K000000 0
072 L000000 24
072 M000000 11
072 N000000 4
072 O000000 0
072 P000000 6
072 Q000000 0
072 R000000 23
072 S000000 9
072 T000000 0
072 U000000 0
072 V000000 0
072 W000000 16
072 X000000 1193
072 Y000000 3
072 Z000000 429
PAGE 8
072AA000000 23549
072BB000000 0
072CC010000 2633
072CC020000 0
072DD010000 5836
072DD020000 0
072EE000000 0
073 A010000 0.7688
073 A020000 0.0000
073 B000000 0.0000
073 C000000 0.0000
074 A000000 1523
074 B000000 0
074 C000000 0
074 D000000 0
074 E000000 0
074 F000000 204658
074 G000000 0
074 H000000 0
074 I000000 12895
074 J000000 9173
074 K000000 0
074 L000000 333
074 M000000 27
074 N000000 228609
074 O000000 13695
074 P000000 178
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 1241
074 R040000 119
074 S000000 0
074 T000000 213376
074 U010000 7592
074 U020000 0
074 V010000 28.11
074 V020000 0.00
074 W000000 0.0000
074 X000000 40
074 Y000000 1535
075 A000000 0
075 B000000 210026
076 000000 27.41
077 A000000 N
078 000000 N
080 C000000 0
081 B000000 0
082 B000000 0
083 B000000 0
084 B000000 0
PAGE 9
086 A010000 0
086 A020000 0
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 09250W107
087 A030000 BME
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 N
SIGNATURE ANNE F. ACKERLEY
TITLE PRESIDENT