<PAGE> PAGE 1
000 A000000 07/31/99
000 C000000 0000759667
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0
000 J000000 U
001 A000000 DREYFUS CASH MANAGEMENT
001 B000000 811-4175
001 C000000 2129226854
002 A000000 200 PARK AVENUE
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10166
002 D020000 0144
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
008 A000001 THE DREYFUS CORPORATION
008 B000001 A
008 C000001 801-8147
008 D010001 NEW YORK
008 D020001 NY
008 D030001 10166
011 A000001 PREMIER MUTUAL FUND SERVICES, INC.
011 B000001 8-13801
011 C010001 NEW YORK
011 C020001 NY
011 C030001 10166
012 A000001 DREYFUS TRANSFER, INC.
012 B000001 85-11312
012 C010001 PROVIDENCE
012 C020001 RI
012 C030001 02940
012 C040001 9671
013 A000001 ERNST & YOUNG LLP
013 B010001 NEW YORK
013 B020001 NY
013 B030001 10019
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
<PAGE> PAGE 2
019 A000000 Y
019 B000000 163
019 C000000 DREYFUSFAM
022 A000001 UBS AG
022 B000001 13-2932996
022 C000001 19005201
022 D000001 0
022 A000002 ASSOCIATES CORPORATION OF NORTH AMERICA
022 B000002 06-0943899
022 C000002 18698948
022 D000002 0
022 A000003 PRUDENTIAL SECURITIES INCORPORATED
022 B000003 22-2347336
022 C000003 11101847
022 D000003 0
022 A000004 REPUBLIC NATIONAL BANK OF NEW YORK
022 B000004 13-2774727
022 C000004 10348859
022 D000004 0
022 A000005 FORD MOTOR CREDIT COMPANY
022 B000005 38-1612444
022 C000005 5648460
022 D000005 0
022 A000006 BARCLAYS DE ZOETE WEDD SECURITIES, INC.
022 B000006 13-3551367
022 C000006 4152868
022 D000006 0
022 A000007 CHASE SECURITIES, INC.
022 B000007 13-3112953
022 C000007 2637383
022 D000007 239728
022 A000008 GOLDMAN, SACHS & CO.
022 B000008 13-5108880
022 C000008 1460515
022 D000008 218346
022 A000009 BANC ONE CAPITAL CORPORATION
022 B000009 31-1017233
022 C000009 1491763
022 D000009 0
022 A000010 GENERAL ELECTRIC CREDIT CORP.
022 B000010 13-1500700
022 C000010 1211032
022 D000010 0
023 C000000 82465416
023 D000000 1739732
024 000000 Y
025 A000001 ASSOCIATES CORPORATION OF NORTH AMERICA
025 B000001 06-0943899
025 C000001 D
025 D000001 119983
025 A000002 GOLDMAN, SACHS & CO.
<PAGE> PAGE 3
025 B000002 13-5108880
025 C000002 D
025 D000002 214967
025 A000003 PRUDENTIAL SECURITIES INCORPORATED
025 B000003 22-2347336
025 C000003 D
025 D000003 99986
025 A000004 UBS AG
025 B000004 13-2932996
025 C000004 D
025 D000004 99986
025 A000005 GENRAL ELECTRIC CAPITAL CORP.
025 B000005 13-1500700
025 C000005 D
025 D000005 566610
025 A000006 REPUBLIC NATIONAL BANK OF NEW YORK
025 B000006 13-2774727
025 C000006 D
025 D000006 98684
026 A000000 Y
026 B000000 Y
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 Y
027 000000 Y
028 A010000 6798563
028 A020000 9340
028 A030000 0
028 A040000 6343472
028 B010000 5182179
028 B020000 8941
028 B030000 0
028 B040000 6515492
028 C010000 4186582
028 C020000 8417
028 C030000 0
028 C040000 4703042
028 D010000 4209527
028 D020000 7065
028 D030000 0
028 D040000 4449846
028 E010000 5143752
028 E020000 6873
028 E030000 0
028 E040000 4756400
028 F010000 4090798
028 F020000 6981
<PAGE> PAGE 4
028 F030000 0
028 F040000 4230418
028 G010000 29611401
028 G020000 47617
028 G030000 0
028 G040000 30998670
028 H000000 0
029 000000 N
030 A000000 0
030 B000000 0.00
030 C000000 0.00
034 000000 N
035 000000 0
036 B000000 0
037 000000 N
038 000000 0
039 000000 N
040 000000 Y
041 000000 Y
042 A000000 52
042 B000000 0
042 C000000 48
042 D000000 0
042 E000000 0
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 759
044 000000 0
045 000000 Y
046 000000 N
047 000000 Y
048 000000 0.200
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
<PAGE> PAGE 5
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 Y
053 C000000 N
054 A000000 Y
054 B000000 Y
054 C000000 Y
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 Y
054 H000000 N
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 Y
054 M000000 Y
054 N000000 N
054 O000000 Y
055 A000000 Y
055 B000000 N
056 000000 N
057 000000 N
058 A000000 N
059 000000 Y
060 A000000 Y
060 B000000 Y
061 000000 10000000
062 A000000 Y
062 B000000 0.0
062 C000000 13.7
062 D000000 0.0
062 E000000 0.0
062 F000000 8.7
062 G000000 0.0
062 H000000 0.0
062 I000000 57.6
062 J000000 1.7
062 K000000 0.0
062 L000000 18.0
062 M000000 0.0
062 N000000 0.0
062 O000000 0.0
062 P000000 0.0
<PAGE> PAGE 6
062 Q000000 0.0
062 R000000 0.0
063 A000000 55
063 B000000 0.0
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 Y
070 B010000 N
070 B020000 N
070 C010000 N
070 C020000 N
070 D010000 N
070 D020000 N
070 E010000 N
070 E020000 N
070 F010000 N
070 F020000 N
070 G010000 N
070 G020000 N
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 N
070 K010000 N
070 K020000 N
070 L010000 N
070 L020000 N
070 M010000 N
070 M020000 N
070 N010000 N
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 0
071 B000000 0
071 C000000 0
071 D000000 0
<PAGE> PAGE 7
072 A000000 6
072 B000000 154449
072 C000000 0
072 D000000 0
072 E000000 0
072 F000000 6204
072 G000000 0
072 H000000 0
072 I000000 0
072 J000000 0
072 K000000 0
072 L000000 0
072 M000000 0
072 N000000 0
072 O000000 0
072 P000000 0
072 Q000000 0
072 R000000 0
072 S000000 0
072 T000000 759
072 U000000 0
072 V000000 0
072 W000000 0
072 X000000 6963
072 Y000000 0
072 Z000000 147486
072AA000000 11
072BB000000 71
072CC010000 0
072CC020000 0
072DD010000 132768
072DD020000 14818
072EE000000 0
073 A010000 0.0000
073 A020000 0.0000
073 B000000 0.0000
073 C000000 0.0000
074 A000000 0
074 B000000 0
074 C000000 5636784
074 D000000 0
074 E000000 0
074 F000000 0
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 0
074 K000000 0
074 L000000 25640
074 M000000 0
074 N000000 5662424
<PAGE> PAGE 8
074 O000000 0
074 P000000 1096
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 5079
074 S000000 0
074 T000000 5656249
074 U010000 5026867
074 U020000 629901
074 V010000 0.00
074 V020000 0.00
074 W000000 0.9994
074 X000000 1829
074 Y000000 0
075 A000000 5601908
075 B000000 0
076 000000 0.00
077 A000000 N
080 C000000 0
081 B000000 0
082 B000000 0
SIGNATURE STEPHANIE D. PIERCE
TITLE ASSIST TREASURER
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000759667
<NAME> DREYFUS CASH MANAGEMENT
<SERIES>
<NUMBER> 3
<NAME> ADMINISTRATIVE SHARES
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-1999
<PERIOD-END> JUL-31-1999
<INVESTMENTS-AT-COST> 5636784
<INVESTMENTS-AT-VALUE> 5636784
<RECEIVABLES> 25640
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 5662424
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 6175
<TOTAL-LIABILITIES> 6175
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 5656767
<SHARES-COMMON-STOCK> 77481
<SHARES-COMMON-PRIOR> 194980
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (518)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 77480
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 154449
<OTHER-INCOME> 0
<EXPENSES-NET> 6963
<NET-INVESTMENT-INCOME> 147486
<REALIZED-GAINS-CURRENT> (60)
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 147426
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (3052)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1374406
<NUMBER-OF-SHARES-REDEEMED> (1493876)
<SHARES-REINVESTED> 2043
<NET-CHANGE-IN-ASSETS> (1339713)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (458)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 6204
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 6963
<AVERAGE-NET-ASSETS> 131811
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> (.023)
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> (.023)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> .003
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000759667
<NAME> DREYFUS CASH MANAGEMENT
<SERIES>
<NUMBER> 1
<NAME> INSTITUTIONAL SHARES
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-1999
<PERIOD-END> JUL-31-1999
<INVESTMENTS-AT-COST> 5636784
<INVESTMENTS-AT-VALUE> 5636784
<RECEIVABLES> 25640
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 5662424
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 6175
<TOTAL-LIABILITIES> 6175
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 5656767
<SHARES-COMMON-STOCK> 5026867
<SHARES-COMMON-PRIOR> 6273830
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (518)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 5026381
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 154449
<OTHER-INCOME> 0
<EXPENSES-NET> 6963
<NET-INVESTMENT-INCOME> 147486
<REALIZED-GAINS-CURRENT> (60)
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 147426
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (132768)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 26271557
<NUMBER-OF-SHARES-REDEEMED> (27560194)
<SHARES-REINVESTED> 41674
<NET-CHANGE-IN-ASSETS> (1339713)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (458)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 6204
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 6963
<AVERAGE-NET-ASSETS> 5601908
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> (.024)
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> (.024)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> .002
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000759667
<NAME> DREYFUS CASH MANAGEMENT
<SERIES>
<NUMBER> 2
<NAME> INVESTOR SHARES
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-1999
<PERIOD-END> JUL-31-1999
<INVESTMENTS-AT-COST> 5636784
<INVESTMENTS-AT-VALUE> 5636784
<RECEIVABLES> 25640
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 5662424
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 6175
<TOTAL-LIABILITIES> 6175
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 5656767
<SHARES-COMMON-STOCK> 499678
<SHARES-COMMON-PRIOR> 462436
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (518)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 499646
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 154449
<OTHER-INCOME> 0
<EXPENSES-NET> 6963
<NET-INVESTMENT-INCOME> 147486
<REALIZED-GAINS-CURRENT> (60)
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 147426
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (10274)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1803358
<NUMBER-OF-SHARES-REDEEMED> (1769791)
<SHARES-REINVESTED> 3674
<NET-CHANGE-IN-ASSETS> (1339713)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (458)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 6204
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 6963
<AVERAGE-NET-ASSETS> 457498
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> (.022)
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> (.022)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> .005
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000759667
<NAME> DREYFUS CASH MANAGEMENT
<SERIES>
<NUMBER> 4
<NAME> PARTICIPANT SHARES
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-1999
<PERIOD-END> JUL-31-1999
<INVESTMENTS-AT-COST> 5636784
<INVESTMENTS-AT-VALUE> 5636784
<RECEIVABLES> 25640
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 5662424
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 6175
<TOTAL-LIABILITIES> 6175
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 5656767
<SHARES-COMMON-STOCK> 52742
<SHARES-COMMON-PRIOR> 65246
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (518)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 52742
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 154449
<OTHER-INCOME> 0
<EXPENSES-NET> 6963
<NET-INVESTMENT-INCOME> 147486
<REALIZED-GAINS-CURRENT> (60)
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 147426
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (1392)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 162080
<NUMBER-OF-SHARES-REDEEMED> (174810)
<SHARES-REINVESTED> 226
<NET-CHANGE-IN-ASSETS> (1339713)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (458)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 6204
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 6963
<AVERAGE-NET-ASSETS> 64103
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> (.022)
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> (.022)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> .006
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
