<PAGE> PAGE 1
000 B000000 12/31/93
000 C000000 752177
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0.a
000 J000000 U
001 A000000 VANGUARD/PRIMECAP FUND, INC.
001 B000000 811-4098
001 C000000 6106691000
002 A000000 100 VANGUARD BOULEVARD
002 B000000 MALVERN
002 C000000 PA
002 D010000 19355
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 75
019 C000000 VANGUARDGR
020 A000001 LEHMAN BROTHERS INC.
020 B000001 13-2518466
020 C000001 27
020 A000002 MERRILL LYNCH PIERCE FENNER & SMITH
020 B000002 13-5674085
020 C000002 27
020 A000003 FIRST BOSTON CORP.
020 B000003 13-5659485
020 C000003 19
020 A000004 LIPPER ANALYTICAL SERVICES
020 B000004 13-2792478
020 C000004 17
020 A000005 ALEX BROWN & SONS
020 B000005 52-0256630
020 C000005 16
020 A000006 SMITH BARNEY SHEARSON
020 B000006 13-1912900
020 C000006 13
020 A000007 MONTGOMERY SECURITIES
020 B000007 94-1701676
020 C000007 13
020 A000008 OPPENHEIMER & CO.
020 B000008 13-2798343
020 C000008 12
020 A000009 RAGEN MACKENZIE INCORPORATED
<PAGE> PAGE 2
020 B000009 91-1374280
020 C000009 12
020 A000010 DEAN WITTER REYNOLDS SECURITIES
020 B000010 94-1671384
020 C000010 12
021 000000 315
022 A000001 THE VANGUARD GROUP, INC./POOLED CASH ACCT.
022 B000001 23-1945930
022 C000001 13518124
022 D000001 0
022 A000002 DONALDSON, LUFKIN & JENRETTE SECURITIES CORP.
022 B000002 13-2741729
022 C000002 0
022 D000002 10424
022 A000003 CANTOR, FITZGERALD & CO., INC.
022 B000003 95-1786286
022 C000003 0
022 D000003 9440
022 A000004 MERRILL LYNCH PIERCE FENNER & SMITH
022 B000004 13-5674085
022 C000004 3368
022 D000004 4372
022 A000005 JONES & ASSOCIATES , INC.
022 B000005 95-3583143
022 C000005 1282
022 D000005 5281
022 A000006 PIPER, JAFFRAY & HOPWOOD INCORPORATED
022 B000006 41-0953246
022 C000006 0
022 D000006 5334
022 A000007 COWEN & CO.
022 B000007 13-5616116
022 C000007 1410
022 D000007 1972
022 A000008 FIRST BOSTON CORP.
022 B000008 13-5659485
022 C000008 1862
022 D000008 0
022 A000009 MORGAN STANLEY & CO., INC.
022 B000009 13-2655998
022 C000009 1370
022 D000009 492
022 A000010 WERTHEIM SCHRODER & CO. INCORPORATED
022 B000010 13-2697272
022 C000010 508
022 D000010 1313
023 C000000 13537704
023 D000000 46712
028 A010000 20343
028 A020000 0
028 A030000 0
<PAGE> PAGE 3
028 A040000 9957
028 B010000 18252
028 B020000 0
028 B030000 0
028 B040000 10988
028 C010000 16001
028 C020000 0
028 C030000 0
028 C040000 31450
028 D010000 22870
028 D020000 0
028 D030000 0
028 D040000 25537
028 E010000 34591
028 E020000 0
028 E030000 0
028 E040000 27258
028 F010000 30381
028 F020000 25026
028 F030000 0
028 F040000 50605
028 G010000 142438
028 G020000 25026
028 G030000 0
028 G040000 155795
028 H000000 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
070 A010000 Y
070 A020000 Y
070 B010000 Y
070 B020000 N
070 C010000 N
070 C020000 N
070 D010000 Y
<PAGE> PAGE 4
070 D020000 N
070 E010000 N
070 E020000 N
070 F010000 Y
070 F020000 N
070 G010000 Y
070 G020000 N
070 H010000 Y
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 Y
070 K010000 Y
070 K020000 N
070 L010000 Y
070 L020000 Y
070 M010000 N
070 M020000 N
070 N010000 Y
070 N020000 Y
070 O010000 Y
070 O020000 N
070 P010000 N
070 P020000 N
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 130081
071 B000000 108115
071 C000000 682710
071 D000000 16
072 A000000 12
072 B000000 1651
072 C000000 6487
072 D000000 0
072 E000000 0
072 F000000 2854
072 G000000 798
072 H000000 0
072 I000000 960
072 J000000 13
072 K000000 0
072 L000000 46
072 M000000 2
072 N000000 0
072 O000000 58
072 P000000 0
072 Q000000 0
072 R000000 9
<PAGE> PAGE 5
072 S000000 0
072 T000000 165
072 U000000 0
072 V000000 8
072 W000000 0
072 X000000 4913
072 Y000000 0
072 Z000000 3225
072AA000000 36460
072BB000000 10924
072CC010000 93538
072CC020000 0
072DD010000 3028
072DD020000 0
072EE000000 25364
073 A010000 0.0700
073 A020000 0.0000
073 B000000 0.5900
073 C000000 0.0000
074 A000000 0
074 B000000 55936
074 C000000 0
074 D000000 0
074 E000000 0
074 F000000 757052
074 G000000 0
074 H000000 0
074 I000000 129
074 J000000 3619
074 K000000 0
074 L000000 5599
074 M000000 0
074 N000000 822335
074 O000000 360
074 P000000 429
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 30649
074 S000000 0
074 T000000 790897
074 U010000 42930
074 U020000 0
074 V010000 18.42
074 V020000 0.00
074 W000000 0.0000
074 X000000 36205
074 Y000000 0
075 A000000 0
075 B000000 733707
<PAGE> PAGE 6
076 000000 0.00
077 A000000 Y
077 B000000 Y
077 C000000 N
077 D000000 N
077 E000000 N
077 F000000 N
077 G000000 N
077 H000000 N
077 I000000 N
077 J000000 N
077 K000000 N
077 L000000 N
077 M000000 N
077 N000000 N
077 O000000 N
077 P000000 N
077 Q010000 N
077 Q020000 N
077 Q030000 N
078 000000 N
080 A000000 ICI MUTUAL INSURANCE COMPANY
080 C000000 110000
081 A000000 Y
081 B000000 91
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 GARY P. SOURA
TITLE ASST.VICE PRESIDENT