| IARS | Illawarra Amateur Radio Society 
| Others |
| IARS | Independent Air Revitalization System
| Others |
| IARS | Indian Association for Reliability and Statistics
| Others |
| IARs | Infusion-Associated Reactions
| Others |
| IARS | Institute for African Renaissance Studies
| Others |
| IARS | International Anesthesia Research Society
| Others |
| IARS | International Atherosclerosis Research School
| Others |
| IARS | International Automated Referral System
| Others |
| IARS | Irish Association of Respiratory Scientists
| Others |