Government and military organizations

• Palestinian Security Services, the armed forces and intelligence agencies of the State of Palestine
• Parliament Security Services, in charge of providing security to the Parliament of India
• Presidential Security Service (South Korea), a South Korean close protection agency

Political parties

• Sammarinese Socialist Party (Italian: Partito Socialista Sammarinese), San Marino
• Senegalese Socialist Party (French: Parti Socialiste Sénégalais)
• Strength of Serbia Movement (Pokret snaga Srbije), a political party in Serbia

Schools

Other businesses and organizations

• Price Stern Sloan, a publishing imprint of Penguin
• Product Support Services, a Microsoft business unit
• PSS World Medical, an American distributor of medical products, equipment, billing services and pharmaceuticals
• Pakistan Statistical Society, an academic and professional society of statisticians
• Społem or PSS Społem, a Polish consumers' co-operative of local grocery stores
• PSS (UK), a British social care charity
• Personal Software Services, a defunct British video game publisher

Biology and medicine

• Perceived Stress Scale, an instrument for measuring perceived stress in humans
• Porcine stress syndrome, a condition in pigs
• Portosystemic shunt, a disease found in humans, cats and dogs
• Progressive systemic sclerosis, a rare chronic disease
• Psychosocial short stature, a growth disorder that is caused by extreme stress

Computing

• Packet Switch Stream, a British packet-switched network
• Packet switching, a method of grouping data that is transmitted over a digital network into packets
• Panorama Software Sys-On-Line
• Passenger service system, systems used by airlines to manage reservations, inventory and check-in
• Performance supervision system, a software system used to improve the performance of a process plant
• Physical symbol system, a hypothesis in artificial intelligence research
• Power system simulator for engineering (PSS®E or PSS/E), software to simulate electrical power transmission networks
• Probabilistic signature scheme, a secure way of creating signatures with RSA
• Proportional set size, a measure of computer program memory use

Physics and chemistry

• Periodic steady-state analysis, type of simulation
• Physica Status Solidi, a family of academic journals focused on solid state physics
• Photostationary state, the equilibrium chemical composition under a specific kind of electromagnetic irradiation
• Plasma sound source, a means of making sonar underwater
• Polystyrene sulfonic acid, also known as sodium polystyrene sulfonate or poly(styrenesulfonate)
• Practical Salinity Scale, the conductivity ratio of a sea water sample to a standard KCl solution

Other uses in technology

• PSS silent pistol, a Soviet-designed silent handgun
• PortaSound PSS series, a series of portable Yamaha keyboards
• Power scale soaring, a form of radio controlled model flying
• Power system stabilizer, in power generation; see Wide-area damping control