Organizations
- Paul Scherrer Institute in Villigen, Switzerland
- Poetry Slam, Inc.
- Policy Studies Institute, a UK organization affiliated with the University of Westminster which undertakes research in matters pertaining to work and social policy and the environment
- Population Services International, an international healthcare NGO based in Washington DC
- Professional Secretaries International
- Professors for a Strong Israel, a right-wing group of academics in Israel
- Psychiatric Solutions, Inc., a corporation that owns psychiatric hospitals
- Public Services International, a global union federation of public sector trade unions
- Statisticians in the Pharmaceutical Industry
- PSI, Contract Research Organization (Pharmaceutical Industry)
Read more about this topic: Psi