PPD
- ACH Network
- Contrast transfer function
- Folding@home
- Mantoux test
- New Mexico
- PPD, Inc.
- PPD-40
- Pani Poni Dash!
- Paranoid personality disorder
- Partito Popolare Democratico Svizzero
- Partners in Population and Development
- Party for Democracy (Chile)
- Pengangkutan Penumpang Djakarta
- Pharmaceutical Product Development
- Pheophorbidase
- Philadelphia Police Department
- Phoenix Police Department
- Pontypridd railway station
- Popular Democratic Party (Puerto Rico)
- PostScript Printer Description
- Postharvest physiological deterioration
- Postpartum depression
- Pour point depressant
- Prevention Project Dunkelfeld
- Protopanaxadiol
- Psychogenic polydipsia
- Published Price to Dealer
- Social Democratic Party (Portugal)
- Sunscreen
- United States Secret Service