| Argos Media | North Holland |
| Aris B.V. | North Brabant |
| Arlanet | North Holland |
| Arletta Pharma Solutions B.V. | |
| Arloz Multimedia | Overijssel |
| Arrix | Friesland |
| Arrow ECS B.V. | |
| Arrow Nederland | Utrecht |
| ArtdCom | |
| Artylicious | North Holland |
| Aryzon 3D B.V. | Overijssel |
| AS Hosting | South Holland |
| ASAP Utilities | Overijssel |
| ASIF Ventures | |
| ASM International N.V. | Flevoland |
| ASML | North Brabant |
| ASROM Computercursus | South Holland |
| Assistent Automatisering | North Brabant |
| AssistiveWare B.V. | |
| AssitYou | South Holland |
| Astrata Europe B.V. | North Brabant |
| ASTRON | |
| Asysco Software B.V. | Drenthe |
| ATAG Benelux | |
| Atai Life Sciences N.V. | |
| Ateïs Europe B.V. | South Holland |
| ATIS Telecommunicatie B.V. | North Holland |
| Atium B.V. | |
| Atlan ICT Services | North Brabant |
| Atlas Internet B.V. | |
| ATM telesignaal | Gelderland |
| ATPS B.V. | Gelderland |
| Atrea | Utrecht |
| ATRO Medical B.V. | |
| ATS International B.V. | North Holland |
| Attached | Utrecht |
| Attingo Datarecovery | North Holland |
| Atto I.T.C. | South Holland |
| Auction-Experts.com | North Holland |
| Audio Ease B.V. | Utrecht |
| Augmedit B.V. | |
| Aura Software B.V. | Utrecht |
| Authic Labs | |
| Auto Interactive B.V. | North Holland |
| AutoBinck | Utrecht |
| AutoExec | North Holland |
| Automatic Solutions | |
| Automatique | South Holland |
| Automatisering Gids | North Holland |
| Automator B.V. | South Holland |