| Acronym | Definition |
|---|
| CISU➣Centro Italiano Studi Ufologici (Italian: Italian Center for Unidentified Flying Object Studies) |
| CISU➣Central Intelligence and Security Unit (Sierra Leone) |
| CISU➣Congregation Israelite Sepharade Unifiee (French: Unified Sephardic Israelite Congregation; Brussels, Belgium) |
| CISU➣Clinical Information Science Unit (University of Leeds; UK) |
| CISU➣Combat Information Systems Unit |
| CISU➣Corporate Information Security Unit |