| EM | Enriched Mantle | - | Computer Acronyms(common) |
| EM | Electron Microscopy | - | Computer Acronyms(common) |
| EM | Emergency | - | Organizations |
| EM | Engineering Model | - | Organizations |
| EM | Exception Monitor | - | Organizations |
| EM | ElectroMagnetic | - | Scuba Diving |
| EM | Excuse Me | - | ISO Country Codes |
| EM | ElectroMagnetism/ElectroMagnetic | - | Astronomy |
| EM | Exametre | - | Astronomy |
| EM | Engineering Model | - | Business and Finance |
| EM | Electromagnetic | - | Business and Finance |
| EM | Electromagnetic Conductivity | - | Business and Finance |
| EM | Electronic Mail | - | Business and Finance |
| EM | Electron Microscope | - | Business and Finance |
| EM | Evaluation Model | - | Business and Finance |
| EM | element manager
| - | Human Genome |
