| ISR | Ice Sheet Reconstruction 
| Others |
| ISR | Ice Speed Record
| Others |
| ISR | Ideal Software Radio
| Others |
| ISR | Illegal Street Racer
| Others |
| ISR | Illegal Street Racing
| Others |
| ISR | In School Restriction
| Others |
| ISR | In Situ Recovery
| Others |
| ISR | In Stent Restenosis
| Others |
| ISR | In-Situ Rinse
| Others |
| ISR | Incremental Software Release
| Others |
| ISR | Independent Sales Representative
| Others |
| ISR | Independent Shifting Rod
| Others |
| ISR | Indirect Source Review
| Others |
| ISR | Individual Safety Report
| Others |
| ISR | Individual Soldier Radio
| Others |
| ISR | Individual Support And Retention
| Others |
| ISR | Individualised Student Record
| Others |
| ISR | Induced Systemic Resistance
| Others |
| ISR | Industry Standard Research
| Others |
| ISR | Infant Swimming Resource
| Others |
| ISR | Infant Swimming Resource's
| Others |
| ISR | Information Security Regulation
| Others |
| ISR | Information Skills Resource
| Others |
| ISR | Information Storage and Retrieval
| Others |
| ISR | Information Systems Research
| Others |
| ISR | Initial State Radiation
| Others |
| ISR | Initial System Release
| Others |
| ISR | Inside Sales Representative
| Others |
| ISR | Installation Status Report
| Others |
| ISR | Institute for Scientific Research
| Others |
| ISR | Institute for Scripture Research
| Others |
| ISR | Institute for Sensory Research
| Others |
| ISR | Institute for Social Research
| Others |
| ISR | Institute for Software Research
| Others |
| ISR | Institute for Survey Research
| Others |
| ISR | Institute for Systems Research
| Others |
| ISR | Institutetute for Social Research
| Others |
| ISR | Institutional Social Responsibility
| Others |
| ISR | Instruction Sampling Recording
| Others |
| ISR | Integrally Suppressed Rifle
| Others |
| ISR | Integrated Services Router
| Others |
| ISR | Integrated Services Router (Cisco)
| Others |
| ISR | Integrated Services Routers
| Others |
| ISR | Integrated Surveillance Resourse
| Others |
| ISR | Integrated Switch Router
| Others |
| ISR | Integrity Service Results
| Others |
| ISR | Intelligence and Space Research
| Others |
| ISR | Intelligence, Surveillance, and Reconnaissance
| Military, Defence, Weapon, Technology, Satellite Technology |
| ISR | Intercept Stabilize And Resolve
| Others |
| ISR | Interdepartmental Service Request
| Others |
| ISR | Intermediate Segregation Regime
| Others |
| ISR | Intermediate Session Routing
| Others |
| ISR | International Schools Review
| Others |
| ISR | International Services Repair
| Others |
| ISR | International Snowmobile Racing
| Others |
| ISR | International Socialist Review
| Others |
| ISR | International Society of Radiology
| Others |
| ISR | International Sports Relations
| Others |
| ISR | International Sportscar Racing
| Others |
| ISR | Internet Security Report
| Others |
| ISR | Internet Service Router
| Others |
| ISR | Interrupt In Service Register
| Others |
| ISR | Interrupt Segment Register
| Others |
| ISR | Interrupt Service Register
| Others |
| ISR | Interrupt Service Routine
| Others |
| ISR | Interrupt Space Register
| Others |
| ISR | Interrupt Status Register
| Others |
| ISR | Intersecting Storage Rings
| Others |
| ISR | Invasive Surgery Remix
| Others |
| ISR | Inventory Sales Ratio
| Others |
| ISR | Inventory Stock Records
| Others |
| ISR | Invoice Summary Register
| Others |
| ISR | Iowa Southern Railroad
| Others |
| ISR | Iowa Southern Railroad Company
| Others |
| ISR | Iterative Survivable Routing
| Others |
| ISR | itial State Radiation
| Others |
| ISR | Self Rescue
| Others |
| ISR | The Indexing Service Reference
| Others |