PPI

PPI may refer to:

Biochemistry

 * PPi, the anion P2O74−, a pyrophosphate
 * Polyproline I helix
 * Protein–protein interaction

Medicine

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

Computing

 * 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

Other science and technology

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

Business and organizations

 * Italian People's Party (1919) (Partito Popolare Italiano), a political party
 * Italian People's Party (1994) (Partito Popolare Italiano), a political party
 * 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
 * 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

Other uses

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