| Eleonora Anzini | Terni |
| Elettra-Sincrotrone Trieste S.C.p.A. | |
| Elettrograf S.r.l. | Padua |
| Elettromatic S.r.l. | Ancona |
| Elettronica 2001 | Bari |
| Elettronica In | Varese |
| Elettronica Montarbo s.r.l. | Macerata |
| Elettrotest S.p.A. | Rovigo |
| Elevel S.r.l. | Ravenna |
| Elex S.r.l. | Turin |
| ELIGO S.r.l. | Milan |
| Elios S.p.A. | Parma |
| Elios.net | Agrigento |
| Elital S.r.l. | |
| Elman-Systems | Milan |
| Elmas Software S.p.A. | Friuli-Venezia Giulia |
| Elmax S.r.l. | Bari |
| ELS Technologies S.r.l. | Syracuse |
| Elsa S.p.A. | Cagliari |
| Elsaidi Software | Viterbo |
| Else Corp S.r.l. | |
| Elsyd S.r.l. | Ravenna |
| Elsynet S.r.l. | Cuneo |
| Elysium Tech S.r.l. | |
| Em3design | Perugia |
| EMAG Software | Rome |
| EmiCAD | Treviso |
| Emitel S.r.l. | Turin |
| Emme Esse S.p.A. | Brescia |
| Emmebistudio S.a.s. | Forlì-Cesena |
| Emmegi S.r.l. | |
| Emmemedia | Naples |
| Emmetek Informatica S.r.l. | Florence |
| Emotiva S.r.l. | |
| Empsol S.r.l. | |
| Enapter S.r.l. | |
| Endian | South Tyrol |
| Endostart S.r.l. | Florence |
| Endurance S.r.l. | Bologna |
| Enel S.p.A. | Rome |
| Enel X Italia S.r.l. | |
| Enerbrain S.r.l. | |
| Energy Dome S.p.A. | Milan |
| Enerpoint S.r.l. | Monza and Brianza |
| EnExSys S.r.l. | Bologna |
| Enforma Solutions | Rovigo |
| Engage Consulting | Ravenna |
| enGenome | Pavia |
| Engine Net S.a.s. | Genoa |
| Engineering Ingegneria Informatica S.p.A. | Rome |