PPI

PPI may refer to:

• PP_i, the anion P₂O₇⁴⁻, a pyrophosphate
• Polyproline I helix
• Protein–protein interaction

• Patient and public involvement
• Prepulse inhibition, of a later pulse
• Proton-pump inhibitor, a class of medications
• Psychopathic Personality Inventory, a personality test
• Psychophysiological Interaction, fMRI analysis technique

• Parallel Peripheral Interface, of the Blackfin processor
• Programmable Peripheral Interface, Intel 8255 chip
• Programmable Peripheral Interconnect, in Nordic nRF microcontrollers
• Pixels per inch, of a display
• Productivity Products International, commercializer of the Objective-C language

• Gabarit passe-partout international, in railways
• Picks per inch, a unit of textile measurement
• Plan position indicator, radar display
• Polymethylene polyphenylene isocyanate

• Italian People's Party (1919) (Partito Popolare Italiano), a political party
• Italian People's Party (1994) (Partito Popolare Italiano), a political party
• Payment protection insurance
• Peace Party of India, Uttar Pradesh
• Perusahaan Perdagangan Indonesia, trading company
• Philips Phonographische Industries, later Philips Records
• Phonographic Performance Ireland, music licensing company
• Pirate Parties International
• Polly Peck International, former UK company
• PPI Holdings, Inc., a Philippine franchisee of restaurant brands
• Primarily Primates, primate sanctuary, Texas, US
• Productivity Products International, US software company later renamed Stepstone
• Progressive Policy Institute, U.S.
• Pakistan Press International, a news agency

• Pareto priority index, to prioritize projects
• Positive polarity item
• Producer price index
• Pulse Polio, immunisation campaign in India
• Port Pirie Airport, IATA airport code "PPI"