| Acronym | Definition |
|---|
| PTI | Pardon The Interruption |
| PTI | Piedmont Triad International (airport code) |
| PTI | Permit To Install |
| PTI | Pittsburgh Technical Institute (Oakdale, Pennsylvania) |
| PTI | Physical Training Instructor |
| PTI | Palomar Testbed Interferometer (observatory) |
| PTI | Parallel Technologies Inc |
| PTI | Pre Trial Intervention |
| PTI | Police Training Institute |
| PTI | Pakistan Tehrik-E-Insaaf |
| PTI | Payment to Income |
| PTI | Parent Training Information Center |
| PTI | Payload Type Indicator |
| PTI | Proof Tracking Index (IEC 60112) |
| PTI | Packet Type Identifier |
| PTI | Parent-Teacher Interview |
| PTI | Primary Trend Index (Richard Russell coined financial analysis term) |
| PTI | Profit-Taking Index |
| PTI | Phoenix Technologies Inc |
| PTI | Personnel Transaction Identifier |
| PTI | Pressure Time Index |
| PTI | Public Training Institute |
| PTI | Programmable Transport Interface |
| PTI | Platform Train Interface (London Underground) |
| PTI | Power Tool Institute, Inc. |
| PTI | Para Tu Información |
| PTI | Presidential Technology Initiative |
| PTI | Planning Time Index |
| PTI | Programmed Test Input |
| PTI | Pharmaceutical Technologies International, Inc |
| PTI | Pacific Telesis International |
| PTI | Protection Technology Idaho (contractor, INEL) |
| PTI | Path Trace Identifier (SDH or Sonet Technology) |
| PTI | Psychotherapists Training Institute (Milford, MA) |
| PTI | Payroll Transfers Inc |
| PTI | Parallel Telemetry Interface (Lucent) |
| PTI | Positive Target Identification (airline security) |
| PTI | Previously Tax Income |
| PTI | Performance Test Instructions (Agilent) |
| PTI | Particulate Trap Inlet |
| PTI | Proposed Technical Improvement |
| PTI | Pyron Technologies, Inc. |
| PTI | Post Tenancy Inspection (UK) |
| PTI | Photon Technology International (various locations) |
| PTI | Public Transport Information |
| PTI | Power to Innovate (UK) |
| PTI | Power Training Institute |
| PTI | Post-Tensioning Institute |
| PTI | Parque Tecnologico Itaipu (Portuguese: Itaipu Technological Park; Brazil) |
| PTI | Printing Technology Inc (Chatsworth, CA) |
| PTI | Public Transport Interchange (various locations) |
| PTI | Press Trust of India |
| PTI | Pretax Income |
| PTI | Proxima Therapeutics Inc. |
| PTI | Public Technology, Inc. |
| PTI | Power Technologies, Inc. |
| PTI | Pattern-Triggered Immunity (plant biology) |
| PTI | Proton Therapy Institute (University of Florida, Jacksonville, FL) |
| PTI | Previously Taxed Income |
| PTI | Pre-Trip Inspection (transportation) |
| PTI | Premier Travel Inn (UK) |
| PTI | Public Technology Institute (Washington, DC) |