| Abbreviation | Definition |
|---|---|
| NIMA | National Integrated Medical Association |
| NIMS | National Institute for Metalworking Skills |
| NINDS | National Institute Of Neurological Disorders And Stroke |
| NINNM | National Institute of Neurology and Neurosurgery of Mexico |
| NIPA | NGOs (Non-Governmental organization) for Integrated Protected Areas |
| NIPD | National Institute for People with Disabilities |
| NISCC | Northern Ireland Social Care Council |
| NISDA | Nantucket Island School of Design and the Arts |
| NISDA | National Independent Schools' Drama Association |
| NISER | National Institute of Science Education and Research (India) |
| NISO | National Information Standards Organization |
| NISO | Network of International Students in Oulu |
| NISOD | National Instituite for Staff and Organizational Development |
| NITE | Naturopathic Institute of Therapies Education |
| NITE | Naturopathic Institute of Therapies & Education |
| NITE | NDTA (Neuro-Developmental Treatment Association) Institute for Training and Education |
| NITI | National Indian Telecommunications Institue |
| NIV | Nederlands Instituut Voor |
| NIWRM | Northern Ireland Women's Rights Movement |
| NIWS | National Institutes for Water Resources |