HISI
| Acronym | Definition |
|---|---|
| HISI | Hospital Infection Society India (New Delhi, India) |
| HISI | Healthcare Informatics Society of Ireland (Cumann Ríomheolais Sláinte) |
| HISI | Heat Illness Symptom Index |
| HISI | Honeywell Information Systems Italia (Milan, Italy) |
| HISI | Hotel Inventories Specialists, Inc |
| HISI | Hotel Interactive Systems, Incorporated (pay-TV provider, Philippines) |