| Enclave Games | |
| Enetech Sp. z o.o. | |
| Eneton Marek Kuczyński | Lubusz |
| Engine Sp. z o.o. | Pomeranian |
| Enovatio Sp. z o.o. | Masovian |
| EnterIT | Lesser Poland |
| Enterso | West Pomeranian |
| Enxoo Sp. z o.o. | Masovian |
| Enzo Sp. z o.o. | Lublin |
| EP&M | West Pomeranian |
| EPA Omnia Sp. z o.o. | West Pomeranian |
| EPC System Outsourcing IT | Masovian |
| Epinote Sp. z o.o. | |
| ePMflow | |
| EPOX Interactive Media House | Masovian |
| EPRO | Podlaskie |
| EQ System | |
| Equitin Advisors Sp. z o.o. | |
| Ergonode Sp. z o.o. | |
| ESB Serwis Sp. z o.o. | Masovian |
| Esbud | Greater Poland |
| ESKOM IT Sp. z o.o. | Masovian |
| ESOD Sp. z o.o. Sp. k. | Greater Poland |
| eSourcing S.A. | |
| Espeo Software Sp. z.o.o. | Greater Poland |
| Esperans-soft | Lower Silesian |
| Esperotia Energy Investments S.A. | |
| Esri Polska | |
| ESTA S.C. | Silesian |
| Estey Sp. z o.o. | Masovian |
| eStrefa.pl | Lesser Poland |
| eTechnologie Sp. z o.o. | |
| eTermo-Inwest Sp. J. | Silesian |
| Etisoft Sp. z o.o. | |
| ETOS Sp. z o.o. | Warmian-Masurian |
| Euleo | |
| Eurobest.pl | Łódź |
| Eurobrand | |
| Euroimpex S.A. | Lower Silesian |
| European University of Information Technology and Economics in Warsaw | |
| Europejska Uczelnia Społeczno-Techniczna im. Roberta Schumana | |
| Europejska Uczelnia w Warszawie | |
| Europejskie Regionalne Centrum Ekohydrologii Polskiej Akademii Nauk | |
| EuroSoft | |
| Evatronix S.A. | Silesian |
| EVE Sp. z o.o. | Masovian |
| Evenea Sp. z o.o. | Masovian |
| Eventory | |
| Eversoft Poland Sp. z o.o. | Masovian |
| Everuptive Sp. z o.o. | |