| Amenit s.r.o. | Moravian-Silesian |
| American Chamber of Commerce in the Czech Republic | |
| Ami Praha, a.s. | Prague |
| Amio | |
| Amos Software, spol. s r.o. | |
| Amotiq | |
| ANECT, a.s. | Prague |
| ANeT-Advanced Network Technology, s.r.o. | South Moravian |
| ANETE, spol. s r.o. | |
| Annex NET, s.r.o. | |
| ANT studio, s.r.o. | |
| Antema | Liberec |
| Antonín Daněk | Prague |
| Apify | |
| Apigenix, s.r.o. | |
| Apollo Multimedia, s.r.o. | Prague |
| Apollo Soft Ltd | |
| Appio | |
| Applic, s.r.o. | Liberec |
| Applifting, s.r.o. | Prague |
| Applifting, s.r.o. | |
| AppSatori, s.r.o. | |
| AQUA, a.s. | |
| Aquila TS, s.r.o. | Pardubice |
| ARBES Technologies, a.s. | Prague |
| ARC-Robotics, s.r.o. | |
| Arcdata Praha, s.r.o. | |
| ARCH LAB, s.r.o. | Olomouc |
| Arelion | |
| ARET Praha, s.r.o. | Prague |
| ARGO22, s.r.o. | |
| Arkance Systems | |
| ART Data s.r.o. | South Moravian |
| ArtFocus | Prague |
| Artic Studio | Central Bohemian |
| Artiffine | |
| ARTIN, spol. s r.o. | South Moravian |
| Artio, s.r.o. | Moravian-Silesian |
| ARTISYS, s.r.o. | |
| As-Happy, a.s. | |
| ASICentrum spol. s r.o. | Prague |
| Asman Production Ltd | |
| ASPone, s.r.o. | Zlín |
| Asseco CEIT, a.s. | |
| Asseco Solutions, a.s. | Prague |
| Assessment Systems | |
| Asys IJD, spol. s r.o. | |
| AT Computers, a.s. | |
| Atlanet media s.r.o. | Olomouc |
| Atlantic18 | South Moravian |