| ISAS | Idaho Science and Aerospace Scholars 
| Others |
| ISAS | Illinois State Academy Of Science
| Others |
| ISAS | Illinois State Archaeological Survey
| Others |
| ISAS | Image Signal Accumulation Sensor
| Others |
| ISAS | Independent Schools Association of the Southwest
| Others |
| ISAS | Independent Suspension Axle System
| Others |
| ISAS | Information Search Analysis Skill
| Others |
| ISAS | Information Search And Analysis Skills
| Others |
| ISAS | Institute for South Asian Studies
| Others |
| ISAS | Institute of Space and Astronautical Science
| Others |
| ISAS | Integrated Statewide Administrative System
| Others |
| ISAS | Interictal SPECT Analysis by SPM
| Others |
| ISAS | International School for Advanced Studies
| Others |
| ISAS | International Service Availability Symposium
| Others |
| ISAS | International Society Of African Scientists
| Others |
| ISAS | International Society of Anglo Saxonists
| Others |
| ISAS | International Society of Anglo-Saxonists
| Others |
| ISAS | International Student Advising Services
| Others |
| ISAS | International Survey of Adult Skills
| Others |
| ISAS | International Symposium On Animal Science
| Others |
| ISAS | Internet Security and Acceleration Server
| Others |
| ISAS | Isdn Smart Attendant Services
| Others |