| Acronym | Definition |
|---|
| PSI➣Pounds per Square Inch |
| PSI➣Packet Switching Interface |
| PSI➣Population Services International |
| PSI➣Psychiatric Solutions Inc. |
| PSI➣Praeger Security International (Santa Barbara, CA) |
| PSI➣Public Services International |
| PSI➣Product Stewardship Institute |
| PSI➣Patient Safety Indicators |
| PSI➣Public Sector Information |
| PSI➣Policy Studies Institute (UK) |
| PSI➣Products and Services, Inc. (various businesses) |
| PSI➣Paul Scherrer Institute (Switzerland, Joint Institute of ETH) |
| PSI➣Political, Social and International Studies (various locations) |
| PSI➣Pet Sitters International |
| PSI➣Pressure per Square Inch (measurement) |
| PSI➣Psionic |
| PSI➣Pre-Shipment Inspection |
| PSI➣Proliferation Security Initiative (international treaty with US DoD mission) |
| PSI➣Publisher Services, Inc. (Norcross, GA) |
| PSI➣Private Sector Involvement |
| PSI➣Project Server Interface (Microsoft) |
| PSI➣Performance Studies International |
| PSI➣Personal Software Inspector |
| PSI➣Performance Systems International |
| PSI➣Personal Services Income (taxes) |
| PSI➣Perimeter Scholars International (physics; Waterloo, Ontario, Canada) |
| PSI➣Plastic Surgery Institute (various locations) |
| PSI➣Penn State Industries |
| PSI➣Presentence Investigation |
| PSI➣Problem-Solving Inventory |
| PSI➣Partito Socialista Italiano |
| PSI➣Printing Services, Inc. (various locations) |
| PSI➣Postpartum Support International |
| PSI➣Pre-Sentence Investigation |
| PSI➣Patient Safety Institute |
| PSI➣Post Script Interpreter |
| PSI➣Published Subject Indicator |
| PSI➣Program Specific Information |
| PSI➣Performance System Integrator |
| PSI➣Prime System Integrator |
| PSI➣Poly Silicon |
| PSI➣Packetnet Systems Interface |
| PSI➣Product Support Integrator |
| PSI➣Privacy Secure Inc. |
| PSI➣Packet Switched Interface |
| PSI➣Program Specific Information (Television) |
| PSI➣Physical Sciences Institute (Illinois) |
| PSI➣Permanent Subcommittee on Investigations (US Senate) |
| PSI➣Pneumonia Severity Index |
| PSI➣Perspectives of System Informatics |
| PSI➣Pitchshifter (band) |
| PSI➣Programa Nacional para la Sociedad de la Información |
| PSI➣Policy Studies Inc (Denver, Colorado) |
| PSI➣Protein Structure Initiative |
| PSI➣Personalized System of Instruction |
| PSI➣Planetary Science Institute |
| PSI➣Physical Sciences Inc. |
| PSI➣Pollutant Standards Index |
| PSI➣Psychological Society of Ireland |
| PSI➣Performance Solutions, Inc. (various locations) |
| PSI➣Paix et Securite Internationales (French) |
| PSI➣Pharmaceutical Society of Ireland |
| PSI➣Public Strategies, Inc. (various locations) |
| PSI➣Postponing Sexual Involvement |
| PSI➣Process Safety Information |
| PSI➣Planned Systems International (Columbia, MD) |
| PSI➣Product Support Integrator (US Army) |
| PSI➣Proteomics Standards Initiative |
| PSI➣Phase Shifting Interferometry |
| PSI➣Police Sub Inspector |
| PSI➣Personnel Security Investigation |
| PSI➣Pharmaceutical Security Institute |
| PSI➣Potentially Shippable Increment (Agile Software Development) |
| PSI➣Promoting Social Inclusion (UK) |
| PSI➣Professional Secretaries International |
| PSI➣Private Sector Initiatives (Houston, TX) |
| PSI➣Plant Sciences Institute |
| PSI➣Public Safety Institute |
| PSI➣Present Serviceability Index (pavement quality rating) |
| PSI➣Professional Services Industries, Inc. |
| PSI➣Statisticians in the Pharmaceutical Industry |
| PSI➣Public Service Indiana |
| PSI➣Pollution Standards Index |
| PSI➣Planning Systems Incorporated |
| PSI➣Preservation Services, Inc. (various locations) |
| PSI➣Patient Safety Initiatives |
| PSI➣Photonic Systems, Inc. (Billerica, MA) |
| PSI➣Pollution Standard Index |
| PSI➣Plant Science Initiative |
| PSI➣Platform Solutions, Inc. (Massachusetts) |
| PSI➣Product Service Innovation |
| PSI➣Principal Security Inspector (aviation) |
| PSI➣Program Systems Institute (Russian Academy of Sciences) |
| PSI➣Polymer Search on the Internet |
| PSI➣Patient Services Incorporated |
| PSI➣Pacific Sustainability Index (Claremont McKenna College; Claremont, CA) |
| PSI➣Produkte Und Systeme Der Informationstechnologie (German stock company) |
| PSI➣Pre-Shift Information (various companies) |
| PSI➣Physicians Services Incorporated (Canada) |
| PSI➣Programmable Serial Interface |
| PSI➣Portuguese Stock Index |
| PSI➣Performance Strategies, Inc. (marketing) |
| PSI➣Performance Sales International |
| PSI➣Pharmaceutical Strategic Initiatives (est. 1985) |
| PSI➣Paul-Scherer-Institut (Switzerland) |
| PSI➣Printempa Semajno Internacia |
| PSI➣Public Service Interpreting |
| PSI➣Aktiengesellschaft für Produkte und Systeme der Informationstechnologie |
| PSI➣Pedestrian Safety Initiative (various locations) |
| PSI➣Project for School Innovation |
| PSI➣Protocol State Information |
| PSI➣Perception, Systèmes, Information |
| PSI➣Philanthropic Service for Institutions |
| PSI➣Protein Synthesis Inhibition |
| PSI➣Pharmacy Services Inc. |
| PSI➣Peripheral Solutions Inc. (Ontario, Canada) |
| PSI➣Pakistan Standards Institution |
| PSI➣Professional Scuba Inspectors, Inc. |
| PSI➣Pinpoint Solutions, Inc. (Steamboat Springs, CO) |
| PSI➣Public Seed Initiative (USDA) |
| PSI➣Priority Solutions International (various locations) |
| PSI➣Professors for a Strong Israel |
| PSI➣Psychiatric Society for Informatics |
| PSI➣Photon Systems Instruments |
| PSI➣Pipeline Systems Inc. |
| PSI➣Political and Social Inquiry |
| PSI➣Perfectly Scientific Inc. |
| PSI➣Panel Source International (Canada) |
| PSI➣Palestine Standards Institution |
| PSI➣Philanthropic Studies Index |
| PSI➣PHP Simple Informer (network services monitor) |
| PSI➣Plasma Source Instrument (NASA) |
| PSI➣Para Su Información (Spanish: For Your Information) |
| PSI➣Portable Scheme Interpreter |
| PSI➣Propagation Systems Inc. |
| PSI➣Project Status Inquiry |
| PSI➣Program Structure Interface (integrated development environments) |
| PSI➣Pitch Synchronous Innovation |
| PSI➣Portable Site Information |
| PSI➣Production/Sales/Inventory |
| PSI➣Parascience International (est. 1976) |
| PSI➣Pechersk School International |
| PSI➣Process Safety Incident |
| PSI➣Professional Support Inc. |
| PSI➣Pipeline Seal and Insulator, Inc. |
| PSI➣Probabilistic and Statistical Inference |
| PSI➣Permanent Staff Instructor (UK military) |
| PSI➣Professional Standards Institute |
| PSI➣Paranormal Science Investigations |
| PSI➣Preliminary Site Inspection |
| PSI➣Pokémon Stars Indonesia (fan club) |
| PSI➣Poseidon Scientific Instruments Pty Ltd |
| PSI➣Partit Socialista de les Illes (Catalan: Socialist Party of the Islands) |
| PSI➣Process Safety Institute |
| PSI➣Parent Success Initiative |
| PSI➣Product Support Initiative |
| PSI➣Progressive Structural Inspection (airframe hour based maintenance and overhaul inspection) |
| PSI➣Present Situations Index |
| PSI➣Projeto de Sistemas de Informação |
| PSI➣Pan-Sahelian Initiative |
| PSI➣Professional Success Institute |
| PSI➣Pre-Screening Interview |
| PSI➣Premium Services Infrastructure |
| PSI➣Program Security Instruction |
| PSI➣Personal Space Invader |
| PSI➣Prism Solutions, Inc. |
| PSI➣Professional Staff Internship |
| PSI➣Personnel Strategies LLC |
| PSI➣Paradigm Shift International |
| PSI➣Program in the Study of Imagination |
| PSI➣Purchase, Sales and Inventory |
| PSI➣Photon Simulation Interface |
| PSI➣Partisan Self Identification |
| PSI➣Process & Systems Integrity |
| PSI➣Planar Spiral Inductor |
| PSI➣Programmable Stratabus Interface |
| PSI➣Prestige Software International |
| PSI➣Paranormal Society of Indiana |
| PSI➣Physical Site Identifier (used to identify a Navy or Marine Corps military installation) |
| PSI➣Public Studies Institute |
| PSI➣Probability, Statistics and Information |
| PSI➣Plan Speed Indicator |
| PSI➣Pollution Standard Indicator |
| PSI➣Peripheral System Interconnect |
| PSI➣Primary Shell Integrity |
| PSI➣Process Sciences, Incorporated |
| PSI➣Pan-Saharan Initiative |
| PSI➣Philosophy Student Initiative |
| PSI➣PBX Switch Interface |
| PSI➣Programmed School Input |
| PSI➣Pilot's Steering Indicator |
| PSI➣Pro Safety International Ltd (UK) |
| PSI➣Promotional Services International |
| PSI➣President's Security Initiative |
| PSI➣Property Standards Index (Australia) |
| PSI➣Press Services of India (India) |
| PSI➣PI Scientific Instrument |
| PSI➣Prior Suspense Item |
| PSI➣ProScuba Inc. |
| PSI➣Personal and Family Safety Information |
| PSI➣Pico-Second Interval |
| PSI➣Pro Salute Imperii (Latin: For Safety of the Empire, epigraphy) |
| PSI➣Product-Specific Sales Incentive |
| PSI➣Program Support Item/Interest |
| PSI➣Pleural Space Infection |
| PSI➣Parallelization/Standardization/Integration |
| PSI➣Programme de Surveillance de l'Irradiation (French: Radiation Monitoring Program) |
| PSI➣Programme de Suivi de l'Irradiation (French: Irradiation Monitoring Program) |