<PAGE>      PAGE  1
000 A000000 11/30/1999
000 C000000 0000835333
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 A
001 A000000 MSDW MUNICIPAL INCOME OPPORTUNITIES TRUST
001 B000000 811-5597
001 C000000 2123922550
002 A000000 TWO WORLD TRADE CENTER
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10048
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
007 C011100 11
007 C011200 12
007 C011300 13
007 C011400 14
007 C011500 15
007 C011600 16
007 C011700 17
007 C011800 18
007 C011900 19
007 C012000 20
007 C012100 21
007 C012200 22
007 C012300 23
007 C012400 24
007 C012500 25
007 C012600 26
007 C012700 27
007 C012800 28
007 C012900 29
<PAGE>      PAGE  2
007 C013000 30
007 C013100 31
007 C013200 32
007 C013300 33
007 C013400 34
007 C013500 35
007 C013600 36
007 C013700 37
007 C013800 38
007 C013900 39
007 C014000 40
007 C014100 41
007 C014200 42
007 C014300 43
007 C014400 44
007 C014500 45
007 C014600 46
007 C014700 47
007 C014800 48
007 C014900 49
007 C015000 50
007 C015100 51
007 C015200 52
007 C015300 53
007 C015400 54
007 C015500 55
007 C015600 56
007 C015700 57
007 C015800 58
007 C015900 59
007 C016000 60
007 C016100 61
007 C016200 62
007 C016300 63
007 C016400 64
007 C016500 65
007 C016600 66
007 C016700 67
007 C016800 68
007 C016900 69
007 C017000 70
007 C017100 71
007 C017200 72
007 C017300 73
007 C017400 74
007 C017500 75
007 C017600 76
007 C017700 77
007 C017800 78
007 C017900 79
007 C018000 80
<PAGE>      PAGE  3
007 C018100 81
007 C018200 82
007 C018300 83
007 C018400 84
007 C018500 85
007 C018600 86
007 C018700 87
007 C018800 88
007 C018900 89
007 C019000 90
008 A000001 MORGAN STANLEY DEAN WITTER ADVISORS INC.
008 B000001 A
008 C000001 801-42061
008 D010001 NEW YORK
008 D020001 NY
008 D030001 10048
010 A000001 MORGAN STANLEY DEAN WITTER SERVICES COMPANY
010 C010001 NEW YORK
010 C020001 NY
010 C030001 10048
011 A000001 DELETE
012 A000001 MORGAN STANLEY DEAN WITTER TRUST FSB
012 B000001 84-1785
012 C010001 JERSEY CITY
012 C020001 NJ
012 C030001 07311
013 A000001 PRICEWATERHOUSECOOPERS LLP
013 B010001 NEW YORK
013 B020001 NY
013 B030001 10036
014 A000001 DEAN WITTER REYNOLDS INC
014 B000001 8-14172
014 A000002 MORGAN STANLEY & CO. INCORPORATED
014 B000002 8-15869
015 A000001 THE BANK OF NEW YORK
015 B000001 C
015 C010001 NEW YORK
015 C020001 NY
015 C030001 10286
015 E010001 X
018  000000 Y
019 A000000 Y
019 B000000  128
019 C000000 MSDW-FUNDS
020 C000001      0
020 C000002      0
020 C000003      0
020 C000004      0
020 C000005      0
020 C000006      0
020 C000007      0
<PAGE>      PAGE  4
020 C000008      0
020 C000009      0
020 C000010      0
021  000000        0
022 A000001 EDWARDS (A.G.) & SONS, INC.
022 B000001 43-0895447
022 C000001      9338
022 D000001      5301
022 A000002 SMITH BARNEY SHEARSON INC.
022 B000002 13-1912900
022 C000002      3248
022 D000002      5151
022 A000003 SIMS (HERBERT J.) & CO,. INC.
022 B000003 13-5213180
022 C000003      6379
022 D000003       442
022 A000004 MORGAN (J.P.) SECURITIES INC.
022 B000004 13-3224016
022 C000004      2000
022 D000004      4610
022 A000005 SALOMON BROTHERS INC.
022 B000005 13-3082694
022 C000005      3000
022 D000005       400
022 A000006 U.S. BANCORP INVESTMENTS
022 B000006 84-1019337
022 C000006         0
022 D000006      3189
022 A000007 LEHMAN BROTHERS INC.
022 B000007 13-2518466
022 C000007      1500
022 D000007      1500
022 A000008 MAXCOR FINANCIAL
022 B000008 13-3410856
022 C000008      2766
022 D000008         0
022 A000009 FIRST ALBANY CORP.
022 B000009 14-1391446
022 C000009         0
022 D000009      1284
022 A000010 MERRILL LYNCH, PIERCE, FEN & SM INC.
022 B000010 13-5674085
022 C000010       600
022 D000010       600
023 C000000      30816
023 D000000      22977
024  000000 N
025 D000001       0
025 D000002       0
025 D000003       0
025 D000004       0
<PAGE>      PAGE  5
025 D000005       0
025 D000006       0
025 D000007       0
025 D000008       0
026 A000000 N
026 B000000 Y
026 C000000 N
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
<PAGE>      PAGE  6
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
044  000000      0
045  000000 Y
046  000000 N
047  000000 Y
048  000000  0.500
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 Y
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 Y
054 H000000 Y
<PAGE>      PAGE  7
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 Y
054 M000000 Y
054 N000000 N
054 O000000 Y
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   1.8
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  97.5
062 P000000   0.0
062 Q000000   0.0
062 R000000   0.0
063 A000000   0
063 B000000 19.0
064 A000000 N
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
<PAGE>      PAGE  8
070 E010000 Y
070 E020000 N
070 F010000 N
070 F020000 N
070 G010000 Y
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 N
070 L010000 Y
070 L020000 N
070 M010000 N
070 M020000 N
070 N010000 Y
070 N020000 N
070 O010000 Y
070 O020000 N
070 P010000 Y
070 P020000 N
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000     15816
071 B000000     16564
071 C000000    172998
071 D000000    9
072 A000000  6
072 B000000     6923
072 C000000        0
072 D000000        0
072 E000000        0
072 F000000      445
072 G000000      267
072 H000000        0
072 I000000       38
072 J000000        4
072 K000000        0
072 L000000       18
072 M000000        9
072 N000000       16
072 O000000        0
072 P000000        0
072 Q000000        0
072 R000000       13
072 S000000        8
<PAGE>      PAGE  9
072 T000000        0
072 U000000        0
072 V000000        0
072 W000000        9
072 X000000      827
072 Y000000        4
072 Z000000     6100
072AA000000      806
072BB000000      592
072CC010000        0
072CC020000     9561
072DD010000     6432
072DD020000        0
072EE000000        0
073 A010000   0.3100
073 A020000   0.0000
073 B000000   0.0000
073 C000000   0.0000
074 A000000      200
074 B000000        0
074 C000000     3100
074 D000000   169187
074 E000000        0
074 F000000        0
074 G000000        0
074 H000000        0
074 I000000        0
074 J000000     3815
074 K000000        0
074 L000000     3924
074 M000000       11
074 N000000   180237
074 O000000     6484
074 P000000      131
074 Q000000        0
074 R010000        0
074 R020000        0
074 R030000        0
074 R040000      148
074 S000000        0
074 T000000   173474
074 U010000    21084
074 U020000        0
074 V010000     8.23
074 V020000     0.00
074 W000000   0.0000
074 X000000     4349
074 Y000000     5708
075 A000000        0
075 B000000   177127
076  000000     8.19
<PAGE>      PAGE  10
077 A000000 N
078  000000 Y
080 C000000        0
081 B000000   0
082 B000000        0
083 B000000        0
084 B000000        0
086 A010000      0
086 A020000      0
086 B010000      6
086 B020000     48
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 STOCK
087 A020000 62621Q101
087 A030000 OIA
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 N
SIGNATURE   BARRY FINK
TITLE       VICE PRESIDENT