PST

Pacific Standard Time, UTC−8:00
Paired Selected Ternary, a pulse transmission plan
Pakistan Standard Time, UTC+5:00
Patient Service Technician, a job title given to a nursing assistant
Percutaneous Skin Test, a clinical test to determine sensitivity to a substance inserted under the skin (also called Skin prick test)
Philippine Standard Time, UTC+8:00
Planar Separator Theorem, a theorem in graph theory
Please Send Tell, an online gaming term that indicates that the person speaking wants to receive private communication
Planescape: Torment, a computer role-playing game
Politiets sikkerhetstjeneste, the Norwegian police security agency
Post-stall technology, aircraft control system
Poznański Szybki Tramwaj, a tram line in Poznań, Poland
Prestonpans railway station, East Lothian, Scotland
Provincial Sales Tax, a sales tax in most Canadian provinces
Program structure tree, a hierarchical representation of computer program structure
Psst, an exclamation to gain attention of someone covertly
.pst, a file extension used for "Personal Folder Files" which store information collected by the Microsoft Outlook application
Lead scandium tantalate, a ceramic material