| Acronym | Definition |
|---|
| PPSI➣Project Preventie Seksuele Intimidatie (Dutch: Sexual Harassment Prevention Project; Utrecht, Netherlands) |
| PPSI➣Pounds Per Square Inch |
| PPSI➣Petroleum Philatelic Society International |
| PPSI➣Paint Product Stewardship Initiative (est. 2005; Product Stewardship Institute) |
| PPSI➣Pharmacists Planning Service, Inc. (health care; California) |
| PPSI➣Printing Press Services International (UK) |
| PPSI➣Porous Polyethylene Sheet Implant |