| Acronym | Definition |
|---|
| GISA | Glycopeptide-Intermediate Staphylococcus Aureus |
| GISA | Georgia Independent School Association |
| GISA | German Information Security Agency |
| GISA | Geographic Information Systems Association of Japan |
| GISA | Genealogiese Instituut van Suid-Afrika (South Africa) |
| GISA | Global Institute for Student Aspirations |
| GISA | General Insurance Statistical Agency (Canada) |
| GISA | Ground Intelligence Support Activity (US Army) |
| GISA | Gestão Integrada de Sistemas de Arquivo |
| GISA | Gemmology Institute of Southern Africa (Port Alfred, South Africa) |
| GISA | Grosse Ile Soccer Association (Grosse Ile, MI) |
| GISA | Geographic Indicator South Australia (wine making) |