| Abbreviation | Definition |
|---|---|
| ISOA | Instrument Society of America |
| ISOAR | Iowa Society of Amateur Rocketeers |
| ISOB | Incorporated Society of Organ Builders |
| ISOB | International Society On Biotelemetry |
| ISOC | Islamic Society of Orange County |
| ISOCS | Indian Society of Cacti Succulents |
| ISOLS | International Society of Limb Salvage |
| ISON | Islamic Society of Nevada |
| ISOO | International Society of Ocular Oncology |
| ISOP | Illinois Society of Periodontists |
| ISOP | Impermanent Society of Philadelphia |
| ISOP | Insurance Society of Philadelphia |
| ISOP | International Society for Ophthalmic Pathology |
| ISOP | International Society For Organ Preservation |
| ISOP | International Society of Pharmacometrics |
| ISOP | International Society of Presbyopia |
| ISOP | International Society of Protistologists |
| ISOP | Israel Society of Pharmacovigilance |
| ISORT | Indiana Society Of Radiologic Technologists |
| ISOSA | Intersex Society of South Africa |