| Libera Università di Bolzano - Bachelor in Computer Science | South Tyrol |
| Libera Università Internazionale degli Studi Sociali Guido Carli | Rome |
| Libersoft | Pisa |
| LICoNet Internet Consulting | South Tyrol |
| LIFEdata S.r.l. | |
| Lifeed | |
| Lifetronic S.r.l. | Pisa |
| Lightstreamer S.r.l. | Milan |
| Liguria Digitale S.p.A. | |
| Limenet S.r.l. | |
| Linea Web S.r.l. | Barletta-Andria-Trani |
| Link-gest S.r.l. | Milan |
| Linkalab S.r.l. | |
| Linkey.it | Parma |
| Linkit S.r.l. | Monza and Brianza |
| Linkwireless | Latina |
| Linux User Group Bolzano-Bozen-Bulsan | South Tyrol |
| Linux User Group Pistoia | Pistoia |
| Linux Users Group Ovest Bresciano | Brescia |
| LinuxSi | |
| LinuxTrent | Trento |
| Lionhealth S.r.l. | |
| Lipogems International S.p.A. | |
| LipsiaSOFT S.r.l. | Varese |
| Liquid Factory | |
| lit - Helios Domotics S.r.l. | |
| Lithium Lasers S.r.l. | |
| Litlyx S.r.l. | |
| Live Tech S.r.l. | |
| livE-Learning | Savona |
| Livecare Support | Milan |
| Livecode | Naples |
| Livit | |
| lmiobrokerassicurativo.it | |
| LN-Studio | Turin |
| Lo.Li. Pharma International S.r.l. | |
| LoanXchain | Milan |
| Loft-Coworking.it | Milan |
| Logel S.r.l. | Modena |
| Logic Sistemi S.r.l. | |
| Logica Informatica | Rome |
| Logical Soft S.r.l. | Monza and Brianza |
| Logical Solutions S.r.l. | Parma |
| Logical Systems | Turin |
| LogicalDOC S.r.l. | Modena |
| Logicamail | Forlì-Cesena |
| Logicamente S.r.l. | Forlì-Cesena |
| Login Informatica S.n.c. | Como |
| Logix S.r.l. | |
| Logon Software | Milan |