Business and economics

Payment card industry, businesses associated with debit, credit, and other payment cards
- Payment Card Industry Data Security Standard, a set of security requirements for credit card processors
Provincial Competitiveness Index, a governance index of Vietnamese provinces
Ceridian-UCLA Pulse of Commerce Index, a U.S. economic indicator based on trucking fuel consumption
Per capita income
Equitable PCI Bank, a Philippine bank

Science and technology

Panel call indicator, telephone signalling system
Pavement condition index, used in transportation civil engineering
Picocurie (pCi), a unit of radioactivity
Peripheral Component Interconnect, a computer bus
- PCI-X (PCI eXtended), a computer bus
- PCI Express (PCIe), a computer bus
Projects of Common Interest, a category of EU projects for interconnecting energy infrastructures
Protocol-control information, in telecommunication
Pulverized coal injection method, in blast furnaces

Percutaneous coronary intervention, a set of procedures used to treat coronary heart disease
Photochemical internalization, a light-triggered drug delivery method
Potato carboxypeptidase inhibitor, a natural peptide usable for thrombolytic and cancer therapy
Prophylactic cranial irradiation, a management option for certain types of aggressive cancers
Protein C inhibitor, a serine protease inhibitor

Paralympic Committee of India, which selects athletes to represent India at international athletic meets
Parti Communiste Internationaliste, a French political party
Partito Comunista Italiano, a former Italian communist party
Peer Community in, communities of researchers reviewing and recommending preprints in their field
Pentecostal Collegiate Institute (New York), 1900–1903, US
Pentecostal Collegiate Institute (Rhode Island), 1902–1918, US
Pharmacy Council of India, a statutory body in India
Porter and Chester Institute, a technical school in Connecticut and Massachusetts, US
Post Carbon Institute, an organization advocating a more resilient, equitable, and sustainable world
Presbyterian Church in Ireland, a Protestant denomination in Ireland
Project Concern International, a humanitarian organization
Public Communications Inc., a Chicago-based national public relations agency