PIEI
| Acronym | Definition |
|---|---|
| PIEI | Partners in Evangelism International (Chicago, IL) |
| PIEI | Pratham India Education Initiative (Mumbai, India) |
| PIEI | Program on International Economic Institutions (Ayacucho, Argentina) |
| PIEI | Percutaneous Intranodular Ethanol Injection |
| PIEI | Positive Ion Electron Ionization |