<PAGE> PAGE 1
000 B000000 09/30/95
000 C000000 0000912492
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 INSTITUTIONAL SHORT TERM TREAS FUND
001 B000000 811-07097
001 C000000 2129226759
002 A000000 200 PARK AVENUE
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10166
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
018 000000 Y
019 A000000 Y
019 B000000 156
019 C000000 DREYFUSFAM
021 000000 0
022 A000001 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
022 B000001 13-5674085
022 C000001 851907
022 D000001 898223
022 A000002 LANSTON (AUBREY G.) & CO. INC.
022 B000002 13-5552129
022 C000002 920769
022 D000002 0
022 A000003 YAMAICHI INTERNATIONAL (AMERICA), INC.
022 B000003 13-5659656
022 C000003 588222
022 D000003 0
022 A000004 DAIWA SECURITIES AMERICA INC.
022 B000004 13-5680329
022 C000004 508109
022 D000004 24954
022 A000005 BARCLAYS DE ZOETE WEDD SECURITIES, INC.
022 B000005 13-3551367
022 C000005 438983
022 D000005 0
022 A000006 THE NIKKO SECURITIES CO. INTERNATIONAL, INC.
022 B000006 94-1302123
022 C000006 361070
022 D000006 0
<PAGE> PAGE 2
022 A000007 GOLDMAN, SACHS & CO.
022 B000007 13-5108880
022 C000007 186628
022 D000007 121266
022 A000008 SALOMON BROTHERS INC.
022 B000008 13-3082694
022 C000008 125218
022 D000008 103996
022 A000009 UBS SECURITIES INC.
022 B000009 13-2932996
022 C000009 83895
022 D000009 100977
022 A000010 FUJI SECURITIES INC.
022 B000010 36-2880742
022 C000010 92322
022 D000010 50754
023 C000000 4590173
023 D000000 1486633
028 A010000 11880
028 A020000 161
028 A030000 0
028 A040000 6099
028 B010000 3628
028 B020000 180
028 B030000 0
028 B040000 7673
028 C010000 44877
028 C020000 258
028 C030000 0
028 C040000 5101
028 D010000 75869
028 D020000 453
028 D030000 0
028 D040000 5616
028 E010000 21417
028 E020000 695
028 E030000 0
028 E040000 8386
028 F010000 11966
028 F020000 644
028 F030000 0
028 F040000 28509
028 G010000 169637
028 G020000 2391
028 G030000 0
028 G040000 61384
028 H000000 0
042 A000000 1
042 B000000 0
042 C000000 99
042 D000000 0
<PAGE> PAGE 3
042 E000000 0
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 35
044 000000 0
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
062 A000000 Y
062 B000000 0.0
062 C000000 0.0
062 D000000 2.9
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 70.5
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 1.7
064 A000000 Y
064 B000000 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
<PAGE> PAGE 4
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 N
070 J020000 N
070 K010000 N
070 K020000 N
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 N
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 1353168
071 B000000 1357218
071 C000000 70246
071 D000000 1926
072 A000000 12
072 B000000 6262
072 C000000 0
072 D000000 0
072 E000000 0
072 F000000 187
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
<PAGE> PAGE 5
072 T000000 35
072 U000000 0
072 V000000 0
072 W000000 0
072 X000000 222
072 Y000000 0
072 Z000000 6040
072AA000000 1955
072BB000000 1937
072CC010000 487
072CC020000 0
072DD010000 5125
072DD020000 886
072EE000000 0
073 A010000 0.1306
073 A020000 0.1263
073 B000000 0.0000
073 C000000 0.0000
074 A000000 813
074 B000000 4806
074 C000000 0
074 D000000 117495
074 E000000 0
074 F000000 0
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 43339
074 K000000 0
074 L000000 2289
074 M000000 0
074 N000000 168742
074 O000000 0
074 P000000 29
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 2001
074 S000000 0
074 T000000 166712
074 U010000 80685
074 U020000 2976
074 V010000 1.99
074 V020000 2.00
074 W000000 0.0000
074 X000000 65
074 Y000000 0
075 A000000 0
075 B000000 79520
076 000000 0.00
<PAGE> PAGE 6
077 A000000 Y
077 B000000 Y
080 A000000 NATIONAL UNION FIRE INS. CO OF PITTSBURGH PA
080 B000000 VIGALANT INSURANCE COMPANY
080 C000000 125
081 A000000 Y
081 B000000 176
082 A000000 N
082 B000000 0
083 A000000 N
083 B000000 0
084 A000000 N
084 B000000 0
085 A000000 Y
085 B000000 N
SIGNATURE JOHN J. PYBURN
TITLE ASSISTANT TREASURER
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000912492
<NAME> DREYFUS INSTITUTIONAL SHORT TERM TREASURY FUND
<SERIES>
<NUMBER> 01
<NAME> CLASS A
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> SEP-30-1995
<PERIOD-END> SEP-30-1995
<INVESTMENTS-AT-COST> 122415
<INVESTMENTS-AT-VALUE> 122301
<RECEIVABLES> 45628
<ASSETS-OTHER> 813
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 168742
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2030
<TOTAL-LIABILITIES> 2030
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 167549
<SHARES-COMMON-STOCK> 80685
<SHARES-COMMON-PRIOR> 46153
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 29
<ACCUMULATED-NET-GAINS> (751)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (115)
<NET-ASSETS> 160748
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 6262
<OTHER-INCOME> 0
<EXPENSES-NET> 222
<NET-INVESTMENT-INCOME> 6040
<REALIZED-GAINS-CURRENT> 18
<APPREC-INCREASE-CURRENT> 487
<NET-CHANGE-FROM-OPS> 6545
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 5125
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 103233
<NUMBER-OF-SHARES-REDEEMED> 1502
<SHARES-REINVESTED> 70203
<NET-CHANGE-IN-ASSETS> 53144
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (769)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 187
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 222
<AVERAGE-NET-ASSETS> 79520
<PER-SHARE-NAV-BEGIN> 1.96
<PER-SHARE-NII> .13
<PER-SHARE-GAIN-APPREC> .03
<PER-SHARE-DIVIDEND> (.13)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.99
<EXPENSE-RATIO> .002
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000912492
<NAME> DREYFUS INSTITUTIONAL SHORT TERM TREASURY FUND
<SERIES>
<NUMBER> 02
<NAME> CLASS B
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> SEP-30-1995
<PERIOD-END> SEP-30-1995
<INVESTMENTS-AT-COST> 122415
<INVESTMENTS-AT-VALUE> 122301
<RECEIVABLES> 45628
<ASSETS-OTHER> 813
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 168742
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2030
<TOTAL-LIABILITIES> 2030
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 167549
<SHARES-COMMON-STOCK> 2976
<SHARES-COMMON-PRIOR> 11753
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 29
<ACCUMULATED-NET-GAINS> (751)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (115)
<NET-ASSETS> 5964
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 6262
<OTHER-INCOME> 0
<EXPENSES-NET> 222
<NET-INVESTMENT-INCOME> 6040
<REALIZED-GAINS-CURRENT> 18
<APPREC-INCREASE-CURRENT> 487
<NET-CHANGE-FROM-OPS> 6545
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 886
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 4899
<NUMBER-OF-SHARES-REDEEMED> 372
<SHARES-REINVESTED> 14048
<NET-CHANGE-IN-ASSETS> 53144
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (769)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 187
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 222
<AVERAGE-NET-ASSETS> 13962
<PER-SHARE-NAV-BEGIN> 1.97
<PER-SHARE-NII> .13
<PER-SHARE-GAIN-APPREC> .03
<PER-SHARE-DIVIDEND> (.13)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 2.00
<EXPENSE-RATIO> .005
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
