<PAGE>
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Form 13F
Form 13F COVER PAGE
Report for the Calendar Year or Quarter Ended: March 31, 1999
Check here if Amendment [ ]; Amendment Number:
--------------
This Amendment (Check only one.): [ ] is a restatement.
[ ] adds new holdings
entries.
Institutional Investment Manager Filing this Report:
Name: Oberweis Asset Management, Inc.
Address: 951 Ice Cream Dr., Suite 200
North Aurora, IL 60542
Form 13F File Number: 28-4688
The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained herein is true, correct and
complete, and that it is understood that all required items, statements,
schedules, lists, and tables, are considered integral parts of this form.
Person signing this Report on Behalf of Reporting Manager:
Name: Patrick B. Joyce
Title: Executive Vice President
Phone: (800) 323-6166
Signature, Place, and Date of Signing:
_________________________ North Aurora, IL April 19, 1999
[Signature] [City, State] [Date]
Report Type (Check only one.):
[X] 13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager
are reported in this report.)
[ ] 13F NOTICE. (Check here if no holdings reported are in this report, and
all holdings are reported by other reporting manager(s).)
[ ] 13F COMBINATION REPORT. (Check here if a portion of the holdings for this
reporting manager are reported in this report and a portion are reported by
other reporting manager(s).)
List of Other Managers Reporting for this Manager:
[If there are no entries in this list, omit this section.]
Form 13F File Number Name
28-4688 _________________________________
[Repeat as necessary.]
<PAGE>
Form 13F SUMMARY PAGE
Report Summary:
Number of Other Included Managers:
-------------------
Form 13F Information Table Entry Total: 142 Data Records
Form 13F Information Table Value Total: $134,935 (thousandths)
List of Other Included Managers:
Provide a numbered list of the name(s) and Form 13F file number(s) of all
institutional investment managers with respect to which this report is filed,
other than the manager filing this report.
[If there are no entries in this list, state "NONE" and omit the column
headings and list entries.]
No. Form 13F File Number Name
28-
---- --------------------- ----------------------
[Repeat as necessary.]
<PAGE>
<TABLE>
<CAPTION>
FORM 13F
March 31, 1999
Value Shares/ Sh/ Put/ Invstmt
Name of Issuer Title of class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers
- --------------------------- -------------- --------- -------- ------- --- ---- ------- ----------
<S> <C> <C> <C> <C> <C> <C> <C> <C>
D ASV Inc. com 001963107 434 25000 SH Sole
D ATI Technologies Inc. com 001941103 499 32600 SH Sole
D Abacus Direct Corp. com 002553105 1517 18500 SH Sole
D Abercrombie & Fitch Co. com 002896207 572 6200 SH Sole
D Action Performance com 004933107 602 20000 SH Sole
D Advance Paradigm Inc. com 007491103 8120 128500 SH Sole
D Advanced Communication com 00750X109 521 44800 SH Sole
D Akorn, Inc. com 009728106 208 50000 SH Sole
D America On Line com 02364J104 1000 6800 SH Sole
D American Eagle Outfitters com 02553D108 3029 42250 SH Sole
D American Healthcorp, Inc. com 02649V104 114 15000 SH Sole
D American Xtal Technology com 030514103 2032 90300 SH Sole
D Analytical Surveys Inc. com 032683302 780 30000 SH Sole
D Andrx Corporation com 034551101 5235 57450 SH Sole
D Apex PC Solutions, Inc. com 037945102 822 59000 SH Sole
D Axent Technologies, Inc. com 05459C108 854 35500 SH Sole
D Biogen Inc. com 090597105 514 4500 SH Sole
D Brightstar Information Technol com 10947N104 108 28000 SH Sole
D Broadcom Corporation com 111320107 1313 21300 SH Sole
D Broadvision Inc. com 111412102 5506 92150 SH Sole
D CGI Group Incorporated Class A com 39945C109 879 40300 SH Sole
D Carrier Access Corporation com 144460102 982 12700 SH Sole
D Catalyst International, Inc. com 14887T105 350 33700 SH Sole
D Chattem Inc. com 162456107 1066 34100 SH Sole
D Check Point Software com M22465104 385 8950 SH Sole
D Chevron Corp. com 166751107 399 4500 SH Sole
D Chico's Fas Inc. com 168615102 1620 75350 SH Sole
D Children's Place com 168905107 1320 49000 SH Sole
D Cinar Corporation com 171905300 460 20000 SH Sole
D Cisco Systems, Inc. com 17275R102 419 3827 SH Sole
D Citrix Systems Inc. com 177376100 530 13900 SH Sole
D Cognicase Inc. com 192423101 877 50830 SH Sole
D Cognizant Technology Solutions com 192446102 1060 38200 SH Sole
D Colorado Medtech, Inc. com 19652U104 977 87800 SH Sole
D Computer Concepts Corp. com 204897300 119 50000 SH Sole
D Compuware Corporation com 205638109 286 12000 SH Sole
D Comtech Telecommunications Cor com 205826209 109 15000 SH Sole
D Concord Communication com 206186108 1738 30500 SH Sole
D Craftmade International Inc. com 22413E104 172 11500 SH Sole
</TABLE>
<TABLE>
<CAPTION>
Voting Authority
----------------------
Name of Issuer Sole Shared None
- --------------------------- ------ ------ ------
<S> <C> <C> <C>
D ASV Inc. 25000
D ATI Technologies Inc. 13000 19600
D Abacus Direct Corp. 18500
D Abercrombie & Fitch Co. 5000 1200
D Action Performance 20000
D Advance Paradigm Inc. 115000 13500
D Advanced Communication 40000 4800
D Akorn, Inc. 50000
D America On Line 4800 2000
D American Eagle Outfitters 35925 6325
D American Healthcorp, Inc. 15000
D American Xtal Technology 62000 28300
D Analytical Surveys Inc. 30000
D Andrx Corporation 44000 13450
D Apex PC Solutions, Inc. 59000
D Axent Technologies, Inc. 28000 7500
D Biogen Inc. 2500 2000
D Brightstar Information Technol 28000
D Broadcom Corporation 19000 2300
D Broadvision Inc. 80000 12150
D CGI Group Incorporated Class A 35000 5300
D Carrier Access Corporation 5500 7200
D Catalyst International, Inc. 25000 8700
D Chattem Inc. 25400 8700
D Check Point Software 5000 3950
D Chevron Corp. 4500
D Chico's Fas Inc. 56000 19350
D Children's Place 46000 3000
D Cinar Corporation 20000
D Cisco Systems, Inc. 2925 902
D Citrix Systems Inc. 9400 4500
D Cognicase Inc. 30000 20830
D Cognizant Technology Solutions 30000 8200
D Colorado Medtech, Inc. 60000 27800
D Computer Concepts Corp. 50000
D Compuware Corporation 7000 5000
D Comtech Telecommunications Cor 15000
D Concord Communication 30000 500
D Craftmade International Inc. 10000 1500
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 13F
March 31, 1999
Value Shares/ Sh/ Put/ Invstmt
Name of Issuer Title of class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers
- ------------------------------ -------------- --------- -------- ------- --- ---- ------- ----------
<S> <C> <C> <C> <C> <C> <C> <C> <C>
D Creative Master Intl., Inc. com 22528Y201 462 77000 SH Sole
D Crystal Systems Solutions com M26763108 378 50000 SH Sole
D Cutter & Buck Inc. com 232217109 1805 56400 SH Sole
D Cybex Computer Products com 232522102 538 30000 SH Sole
D DM Management Company com 233233105 437 28000 SH Sole
D Display Technologies Incorpora com 25469V102 266 51350 SH Sole
D Engineering Animation Inc. com 292872108 352 8350 SH Sole
D FDX Corporation com 31304N107 309 3320 SH Sole
D Factset Research Systems com 303075105 662 15300 SH Sole
D Family Golf Centers com 30701A106 446 60000 SH Sole
D First Consulting Group com 31986R103 758 68100 SH Sole
D First South Africa com G34874100 22 10000 SH Sole
D Forsoft Limited com m46544108 247 30000 SH Sole
D Four Media Company com 350872107 180 30000 SH Sole
D Frenchtex com 357814102 11 25000 SH Sole
D Gemstar International Group com G3788V106 309 4100 SH Sole
D Genesis Microchip Inc. com 371933102 2299 96800 SH Sole
D Gentner Communications com 37245J105 331 106000 SH Sole
D Geotel Communications Co. com 373656107 670 14600 SH Sole
D Gilat Communications, Ltd. com M50876107 1465 105100 SH Sole
D Gliatech, Inc. com 37929C103 920 39800 SH Sole
D Global Payment Technology Inc. com 37936s109 196 18000 SH Sole
D Great Plains Software com 39119E105 809 20900 SH Sole
D HMG Worldwide Corp. com 404235103 202 50000 SH Sole
D Hain Food Group Inc com 405219106 744 45100 SH Sole
D Happy Kids, Inc. com 411391105 331 33100 SH Sole
D Home Depot Inc. com 437076102 240 3859 SH Sole
D IMRglobal Corporation com 45321W106 177 10000 SH Sole
D Icon PLC com 45103t107 232 16000 SH Sole
D Impath, Inc. com 45255G101 1573 64200 SH Sole
D Infocure Corporation com 45665A108 371 13300 SH Sole
D Innotrac Corporation com 45767M109 247 15000 SH Sole
D Innovative Medical Services com 45766r109 37 50000 SH Sole
D Intel Corporation com 458140100 255 2145 SH Sole
D Interlinq Software Corporation com 458753100 77 10000 SH Sole
D International Fibercom Inc. com 45950T101 922 140500 SH Sole
D Intl Network Services com 460053101 210 3000 SH Sole
D Jakks Pacific Inc. com 47012E106 1276 69000 SH Sole
D Javelin Systems, Inc. com 471896100 3920 323300 SH Sole
</TABLE>
<TABLE>
<CAPTION>
Voting Authority
--------------------------
Name of Issuer Sole Shared None
- ------------------------------ ------- -------- --------
<S> <C> <C> <C>
D Creative Master Intl., Inc. 60000 17000
D Crystal Systems Solutions 50000
D Cutter & Buck Inc. 45000 11400
D Cybex Computer Products 30000
D DM Management Company 28000
D Display Technologies Incorpora 40000 11350
D Engineering Animation Inc. 6000 2350
D FDX Corporation 700 2620
D Factset Research Systems 15300
D Family Golf Centers 60000
D First Consulting Group 60000 8100
D First South Africa 10000
D Forsoft Limited 30000
D Four Media Company 30000
D Frenchtex 25000
D Gemstar International Group 2500 1600
D Genesis Microchip Inc. 50000 46800
D Gentner Communications 60000 46000
D Geotel Communications Co. 4000 10600
D Gilat Communications, Ltd. 77000 28100
D Gliatech, Inc. 25000 14800
D Global Payment Technology Inc. 15000 3000
D Great Plains Software 18000 2900
D HMG Worldwide Corp. 50000
D Hain Food Group Inc 30000 15100
D Happy Kids, Inc. 20000 13100
D Home Depot Inc. 2000 1859
D IMRglobal Corporation 10000
D Icon PLC 12000 4000
D Impath, Inc. 60000 4200
D Infocure Corporation 12000 1300
D Innotrac Corporation 15000
D Innovative Medical Services 50000
D Intel Corporation 700 1445
D Interlinq Software Corporation 10000
D International Fibercom Inc. 100000 40500
D Intl Network Services 3000
D Jakks Pacific Inc. 40000 29000
D Javelin Systems, Inc. 254000 69300
</TABLE>
2
<PAGE>
<TABLE>
<CAPTION>
FORM 13F
March 31, 1999
Value Shares/ Sh/ Put/ Invstmt
Name of Issuer Title of class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers
- ----------------------------- --------------- --------- -------- ------- --- ---- ------- ----------
<S> <C> <C> <C> <C> <C> <C> <C> <C>
D Kendle International, Inc. com 48880L107 1612 80100 SH Sole
D King Pharmaceuticals Inc. com 495582108 2844 102500 SH Sole
D Lason, Inc. com 51808R107 281 5000 SH Sole
D MIM Corporation com 553044108 58 25000 SH Sole
D Made2Manage, Inc. com 556466100 1831 209300 SH Sole
D Manatron Inc. com 562048108 196 36500 SH Sole
D Medquist Inc. com 584949101 1260 42000 SH Sole
D Memberworks, Inc. com 586002107 1058 29200 SH Sole
D Merck & Co. com 589331107 248 3100 SH Sole
D Metzler Group Inc. com 592903108 1675 53400 SH Sole
D Micromuse Incorporated com 595094103 460 10000 SH Sole
D Microsoft Corp. com 594918104 291 3250 SH Sole
D Mindspring Enterprises com 602683104 6803 79050 SH Sole
D Mobil Corp. com 607059102 546 6200 SH Sole
D Motorola Inc. com 620076109 308 4203 SH Sole
D Network Appliance Inc. com 64120L104 2065 40800 SH Sole
D New Dimension Software Limited com M74295102 1037 20000 SH Sole
D New Era Of Networks com 644312100 752 11100 SH Sole
D New Horizons Worldwide com 645526104 199 10000 SH Sole
D Open Text Corporation com 683715106 1852 58790 SH Sole
D Osteotech Inc. com 688582105 1743 50700 SH Sole
D P.F. Changs China Bistro com 69333y108 439 14400 SH Sole
D Papa John's International Inc. com 698813102 1986 45000 SH Sole
D Perclose Inc. com 71361C107 986 31800 SH Sole
D Peregrine Systems com 71366Q101 807 24000 SH Sole
D Pfizer Inc. com 717081103 430 3100 SH Sole
D Qiagen N.A. com 730000106 2350 34500 SH Sole
D Qlogic Corp com 747277101 2509 37380 SH Sole
D Quadramed Corporation com 74730W101 229 30000 SH Sole
D Questron Technology, Inc. com 748372208 79 20000 SH Sole
D RCM Technologies com 749360400 538 48900 SH Sole
D RF Micro Devices, Inc. com 749941100 2866 29950 SH Sole
D Railamerica Inc. com 750753105 175 20000 SH Sole
D Rehabilicare Incorporated com 758944102 52 20000 SH Sole
D Rent-Away Inc. com 760090104 360 15000 SH Sole
D Resmed Inc. com 761152107 565 20000 SH Sole
D Roberts Pharmaceutical com 770491108 239 11500 SH Sole
D SCM Microsystems com 784018103 204 3350 SH Sole
D Salton Inc. com 795757103 2959 121100 SH Sole
</TABLE>
<TABLE>
<CAPTION>
Voting Authority
-------------------------
Name of Issuer Sole Shared None
- ----------------------------- ------ -------- --------
<S> <C> <C> <C>
D Kendle International, Inc. 68400 11700
D King Pharmaceuticals Inc. 80000 22500
D Lason, Inc. 5000
D MIM Corporation 25000
D Made2Manage, Inc. 166000 43300
D Manatron Inc. 20000 16500
D Medquist Inc. 42000
D Memberworks, Inc. 25000 4200
D Merck & Co. 1600 1500
D Metzler Group Inc. 50000 3400
D Micromuse Incorporated 10000
D Microsoft Corp. 1000 2250
D Mindspring Enterprises 63000 16050
D Mobil Corp. 6200
D Motorola Inc. 4203
D Network Appliance Inc. 40000 800
D New Dimension Software Limited 20000
D New Era Of Networks 10300 800
D New Horizons Worldwide 10000
D Open Text Corporation 40000 18790
D Osteotech Inc. 45000 5700
D P.F. Changs China Bistro 10000 4400
D Papa John's International Inc. 45000
D Perclose Inc. 25000 6800
D Peregrine Systems 24000
D Pfizer Inc. 2000 1100
D Qiagen N.A. 34500
D Qlogic Corp 25000 12380
D Quadramed Corporation 30000
D Questron Technology, Inc. 20000
D RCM Technologies 30000 18900
D RF Micro Devices, Inc. 22000 7950
D Railamerica Inc. 20000
D Rehabilicare Incorporated 20000
D Rent-Away Inc. 15000
D Resmed Inc. 20000
D Roberts Pharmaceutical 8000 3500
D SCM Microsystems 1400 1950
D Salton Inc. 100000 21100
</TABLE>
3
<PAGE>
FORM 13F
March 31, 1999
<TABLE>
<CAPTION>
Value Shares/ Sh/ Put/ Invstmt
Name of Issuer Title of class CUSIP (x$1000) Prn Amt Prn Call Dscretn Managers
- ---------------------------- ---------------- --------- -------- ------- --- ---- ------- ----------
<S> <C> <C> <C> <C> <C> <C> <C> <C>
D Sapient Corporation com 803062108 856 12000 SH Sole
D Select Comfort Corporation com 81616x103 279 10000 SH Sole
D Siebel Systems Inc. com 826170102 560 11800 SH Sole
D Softworks, Inc. com 83404P102 547 38400 SH Sole
D Spectralink Corp. com 847580107 377 100600 SH Sole
D Staffmark, Inc. com 852389105 315 40000 SH Sole
D Stericycle, Inc. com 858912108 672 50000 SH Sole
D Steven Madden Ltd. com 556269108 211 25000 SH Sole
D Sunrise Assisted Living com 86768K106 957 21000 SH Sole
D Suprema Specialties, Inc. com 86859f107 540 116800 SH Sole
D Symix Systems Inc. com 871535100 546 35800 SH Sole
D Synthetech Inc. com 87162c100 153 35000 SH Sole
D Tava Technologies com 872169107 125 25000 SH Sole
D Telecomm Industries Corp. com 87928B101 90 115000 SH Sole
D Tier Technologies com 88650Q100 545 62700 SH Sole
D Transwitch Corporation com 894065101 1670 36900 SH Sole
D Tricom, S.A. com 89612a100 289 35000 SH Sole
D Veritas Software Corp. com 923436109 2374 29400 SH Sole
D Verity Inc. com 92343C106 2743 81890 SH Sole
D Vermont Pure Holdings com 924234107 74 20000 SH Sole
D Visx Inc. Del com 92844S105 323 3000 SH Sole
D Vitesse Semiconductor Co. com 928497106 496 9800 SH Sole
D Waters Corporation com 941848103 263 2500 SH Sole
D Xeikon NV ADR com 984003103 1142 41700 SH Sole
D Xircom, Inc. com 983922105 1680 66850 SH Sole
S REPORT SUMMARY 142 DATA RECORDS 134935 0 OTHER MANAGERS ON WHOSE
BEHALF REPORT IS FILED
</TABLE>
<TABLE>
<CAPTION>
Voting Authority
-----------------------------
Name of Issuer Sole Shared None
- ---------------------------- ------- ----------- ------
<S> <C> <C> <C>
D Sapient Corporation 12000
D Select Comfort Corporation 10000
D Siebel Systems Inc. 7600 4200
D Softworks, Inc. 25000 13400
D Spectralink Corp. 38000 62600
D Staffmark, Inc. 40000
D Stericycle, Inc. 50000
D Steven Madden Ltd. 25000
D Sunrise Assisted Living 20200 800
D Suprema Specialties, Inc. 46400 70400
D Symix Systems Inc. 29000 6800
D Synthetech Inc. 35000
D Tava Technologies 25000
D Telecomm Industries Corp. 115000
D Tier Technologies 60000 2700
D Transwitch Corporation 30000 6900
D Tricom, S.A. 16000 19000
D Veritas Software Corp. 29400
D Verity Inc. 51500 30390
D Vermont Pure Holdings 20000
D Visx Inc. Del 3000
D Vitesse Semiconductor Co. 7600 2200
D Waters Corporation 1500 1000
D Xeikon NV ADR 40000 1700
D Xircom, Inc. 52100 14750
S REPORT SUMMARY
</TABLE>
