| Link | ABS Ventures | Palo Alto | | iLumin, Sequoia Media Group | 1 | $300,000 | |
| Link | Acacia Venture Partners | San Francisco | California | | 1 | $750,000 | Medical Devices |
 | Accel | Palo Alto | | | 3 | $30,000,000 | Communications Content & Media Information Services Electronics Software Security |
 | Advanced Equities | Chicago | | Echopass | 1 | | Communications Content & Media Electronics Software Services Storage Energy |
| Link | Advent International | Boston | | Spreeride, Inc. | 3 | $33,750,000 | Biotechnology Communications Electronics Services Storage Advanced Materials Energy |
| Link | Aether Capital | Owings Mills | Maryland | Mainstream Data, Inc | | | |
| AIG Capital Partners | Fair Oaks | California | | 1 | $3,000,000 | |
| Link | Akers Capital | Fair Oaks | California | OnePipeline | | | Communications |
| Link | Albion Investors | New York | New York | | | | |
| Link | Alerion Capital Group | Salt Lake City | | | 1 | | Communications Information Services Electronics Software Storage Security |
 | Allegis Capital | Santa Monica | | Allegiance, Inc | 1 | $950,000 | Communications Information Services Electronics Software Services Security |
| Link | Allen & Buckeridge Pvt Ltd. | Sydney | | | 1 | $1,500,000 | |
| Link | AllianceBernstein | New York | New York | OnePipeline | | | Biotechnology Information Services Electronics Software |
| Link | Alta Communications | Boston | Massachusetts | | 1 | $5,890,000 | Communications Content & Media |
 | American River Ventures | Roseville | | | 1 | $2,280,000 | Communications Electronics Software Advanced Materials Research |
| Link | Amerindo Investment Advisors | | | Campus Pipeline, The Generations Network | | | Information Services Electronics Storage |
 | Amerivon Holdings | Incline Village | | Sequoia Media Group | 1 | | Electronics Software |
| Link | AMP Capital Investors | Sydney | | NextPage, Senforce Technologies, Inc | 1 | $11,220,000 | |
| Link | Ampersand Venture Management | Wellesley | Massachusetts | Iomega | 1 | | Biotechnology Communications Electronics Healthcare Services Software |
| Link | Apax Partners Worldwide | New York | New York | | 1 | $9,880,000 | Biotechnology Communications Content & Media Information Services Electronics Software Energy Security |
| Link | APV Technology Partners | Palo Alto | | IBAHN | 4 | $31,390,000 | Electronics |
| Link | Argosy Investment Partners | Wayne | Pennsylvania | FatPipe Networks | | | |
| Ash Capital | Los Angeles | | Agilix Labs, Inc, Venafi, Inc | 2 | | Software |
 | Aspen Grove Ventures | Mesa | | | | | Software |
| Link | Aspen Ventures | | | | | | |
| Link | Asset Management Company | Palo Alto | California | Sonic Innovations | | | Biotechnology Communications Information Services Hardware Software Medical Devices |
| Link | Attractor Investment Management | Burlingame | California | Omniture Inc | 1 | $4,200,000 | |
| AV Capital | | | | 1 | $600,000 | |
|