GISI
| Acronym | Definition |
|---|---|
| GISI | Graphic Imaging Services, Inc. (Las Vegas, NV) |
| GISI | Gruppo Imprese Strumentazione Italia (Italian: Enterprise Instrumentation Group Italy) |
| GISI | Gereja Injil Seutuh Indonesia (Indonesian gospel church) |
| GISI | Group Insurance Solutions, Inc. |
| GISI | Gruppo Italiano Studio Ipovisione (Italian: Italian Low Vision Study Group) |
| GISI | Global Invasive Species Initiative |