PISI
| Acronym | Definition |
|---|---|
| PISI | Pine Siskin (bird species) |
| PISI | Port-Injection Spark-Ignition (engine) |
| PISI | Palpap Ichinichi Software International (India) |
| PISI | Palmar Intercalated Segment Instability (hand ligaments) |
| PISI | Prudentialife Information Systems, Inc. (Makati, Philippines) |
| PISI | Prognostic Index of Surgical Infections (gastroenterology) |