| Cadbury Poland |
| - chocolate and sweets producer. |
| Carcade |
| - a leasing company in Warsaw. |
| Case Sp. z o.o. |
| - market research. |
| Centre of New Technologies |
| - provides online services in Gdansk. |
| Centrozap |
| - Polish trading house specializing in heavy industries. |
| Clico |
| - Polish software developer. |
| Coal Company of Gliwice |
| Colgate-Palmolive Poland |
| - cosmetics. |
| Commercial Union |
| - insurance. |
| Coopers & Lybrand Poland |
| Coopers & Lybrand Poland |
| - provides professional services including accounting and auditing, tax and consulting. |
| CSBI SA |
| - computers. |
| Cyfronet |