| IRSA | Ibm Rational Software Architect 
| Others |
| IRSA | Immigration and Refugee Services of America
| Others |
| IRSA | Independent Railway Supervisors Association
| Others |
| IRSA | Indian River Soccer Association
| Others |
| IRSA | Indiana Recreational Sports Association
| Others |
| IRSA | Indonesian Regional Science Association
| Others |
| IRSA | Indus River System Authority
| Others |
| IRSA | Industry Road Safety Alliance
| Others |
| IRSA | Institute of Remote Sensing Applications
| Others |
| IRSA | Institute Of Risk And Safety Analysis
| Others |
| IRSA | Intelligent Full Range Speed Assistant
| Others |
| IRSA | Interior Rally Sport Association
| Others |
| IRSA | International Radio Sailing Association
| Others |
| IRSA | International RadioSurgery Association
| Others |
| IRSA | International Relations Students
| Others |
| IRSA | International Relations Students Association
| Others |
| IRSA | International Rett Syndrome Association
| Others |
| IRSA | International Road Safety Academy
| Others |
| IRSA | International Rural Sociology Association
| Others |
| IRSA | Interventional Radiology Society of Australasia
| Others |
| IRSA | Inversiones y Rentas, S.A.
| Others |
| IRSA | Irish Research Scientists' Association
| Others |
| IRSA | Irish Research Staff Association
| Others |