BISI
| Acronym | Definition |
|---|---|
| BISI | Background Information Services Inc. (Boulder, CO) |
| BISI | British Institute for the Study of Iraq (est. 1932; UK) |
| BISI | British International School Istanbul (Turkey) |
| BISI | Bielski Internetowy Serwis Informacyjny (Polish: Bielski Internet Information Service) |
| BISI | Bloggers in Support of Israel |
| BISI | Billing Integration Strategy Implementation |