| Abbreviation | Definition |
|---|---|
| ISAP | International Society for Archaeological Prospection |
| ISAP | International Society of Anti-Infective Pharmacology |
| ISAR | International Society for Antiviral Research |
| ISAR | International Society for Astrological Research |
| ISAT | International Schools Association Of Thailand |
| ISATP | International Society of Anti-Terrorism Professionals |
| ISBA | International Society of Business Administrators |
| ISBA | International Society of Business Astrologers |
| ISBM | International Society of Behavioral Medicine |
| ISBS | International Society for Biophysics and Imaging of the Skin |
| ISCC | International Securities Clearing Corporation |
| ISCD | International Society for Clinical Densitometry |
| ISCEBS | International Society of Certified Employee Benefit Specialists |
| ISCM | International Society of Configuration Management |
| ISDA | International Swaps and Derivatives Association |
| ISDA | International Systems Dealers Association |
| ISDS | Illinois State Dental Society |
| ISDSI | Insulated Steel Door Systems Institute |
| ISEA | Industrial Safety Equipment Association |
| ISED | Institute of Small Enterprises and Development |