| IU | Imaging Unit
| Others |
| IU | Immunizing unit
| Others |
| IU | Imperial Units
| Others |
| IU | Independence of Underlined
| Others |
| IU | Indiana University
| Others |
| IU | Indianapolis Union
| Others |
| IU | Indianapolis Union Railway
| Others |
| IU | Individual Unemployable
| Others |
| IU | Individual Unit
| Others |
| IU | Inebriated and Underage
| Others |
| IU | Infinite Universe
| Others |
| IU | Information Unit
| Others |
| IU | Instructional Unit
| Others |
| IU | Instrument Unit
| Others |
| IU | Insulated Underwear
| Others |
| IU | Integrated Unit
| Others |
| IU | Intensity Units
| Others |
| IU | Intermediate Unit
| Others |
| IU | Internal Use
| Others |
| IU | International Unit
| Others |
| IU | International Units
| Others |
| IU | Internet Update
| Others |
| IU | IntraUterine
| Others |
| IU | Istanbul University
| Others |
| IU | Item Upgrade
| Others |
| IU | Izquierda Unida
| Others |