| Acronym | Definition |
|---|
| EFI | Electronic Fuel Injection |
| EFI | Electronics For Imaging |
| EFI | Extensible Firmware Interface (Intel) |
| EFI | Energy for Industry (various locations) |
| EFI | Energy Federation Incorporated |
| EFI | Error Free Interval |
| EFI | Extensible Firmware Interface |
| EFI | European Forest Institute |
| EFI | Enterprise Florida Inc. |
| EFI | Euro-Foncier Immobilier (French: Euro-Land Real Estate) |
| EFI | Evangelical Fellowship of India |
| EFI | European Federation for Immunogenetics (formerly European Foundation for Immunogenetics) |
| EFI | Enrico Fermi Institute (University of Chicago) |
| EFI | Electric Field Instrument (on POLAR) |
| EFI | Early French Immersion (Canadian language education program) |
| EFI | Electronic Flight Instrument (aviation) |
| EFI | Electromechanical Frequency Interference |
| EFI | Environic Foundation International (Glen Allen, VA) |
| EFI | Exploding Foil Initiator |
| EFI | Environment Furniture, Inc. (various locations) |
| EFI | Europe France Inventeurs (French inventors association) |
| EFI | Engineer, Furnish, and Install (telecommunications) |
| EFI | Expeditionary Forces Institute (UK) |
| EFI | École de Football Intercommunale (French: Intermunicipal Football School) |
| EFI | European Foundation for Immunogenetics (now European Federation for Immunogenetics) |
| EFI | external fuel injection |
| EFI | Electronic Flash Illuminator |
| EFI | Elektrisitetsforsyningens Forskninginstitutt (Norwegian Electric Power Research Institute) |
| EFI | Engineering Function Instruction |