NHSI
| Acronym | Definition |
|---|---|
| NHSI | National High School Invitational (basketball event) |
| NHSI | National High School Institute (est. 1931; Northwestern University; Evanston, IL) |
| NHSI | National Health Services, Inc. (California) |
| NHSI | National Health Surveillance Infostructure (Health Canada) |
| NHSI | National Healthcare Solutions, Inc. |
| NHSI | Normal-to-High Salt Intake (nutritional science) |