| MegaSpider | Rome |
| Meginet S.r.l. | Naples |
| Melazeta S.r.l. | Modena |
| Memopal | Milan |
| Memopal | Rome |
| Men in Web | Forlì-Cesena |
| Menarini Silicon Biosystems S.p.A. | |
| Menhir Computers | Macerata |
| Mercurius BI S.r.l. | Milan |
| Meridiaweb | Taranto |
| Meritocracy | Milan |
| MerlinWizard | Milan |
| Messagenet S.p.A. | Milan |
| MET S.r.l. | Milan |
| Meta System S.p.A. | Reggio Emilia |
| Metacasa S.r.l. | |
| Metacortex | Rome |
| Metaf | Siena |
| Metaliquid S.r.l. | |
| Metamarketing Service S.r.l. | Prato |
| Metaphor | Milan |
| Metaphora | Milan |
| Metatheory Studio | |
| Metatron S.p.A. | |
| Metaventure1 holding S.r.l. | |
| Metaverso | Treviso |
| Metis Systems S.r.l. | Rome |
| Metisoft S.p.A. | |
| Mezzi Comunicazione Audiovisiva S.r.l. | Milan |
| MG Soft | Monza and Brianza |
| MGH7 Venture Capital | Milan |
| MGquadro S.r.l. | Rome |
| MgShell S.r.l. | |
| MGvision S.r.l. | Rome |
| Mia-Platform | Milan |
| Michele Baldoni | Milan |
| Microarea S.p.A. | Genoa |
| Microcontrol Electronic S.r.l. | |
| Microdevice s.r.l. | Brescia |
| Microfinanza Rating S.r.l. | |
| Microgame S.p.A. | |
| Microntel S.p.A. | Turin |
| Micropto S.r.l. | Milan |
| Microrex S.r.l. | Milan |
| Microsales | Palermo |
| Microsoft Italy | Milan |
| Microsys S.r.l. | Milan |
| MicroSystems S.p.A. | Modena |
| Microsystemweb | Novara |
| Microtech Retail S.r.l. | |