The Zasavje statistical region is situated in the centre of Slovenia and covers three municipalities: Hrastnik, Trbovlje and Zagorje ob Savi. It is the smallest Slovene region population and surface wise. The region is facing fast transformation: from once traditional heavy industrial (coal-mining and energetics) to a modern environment.
| Municipality | Population | Surface |
| Hrastnik | 10.298 | 59km2 |
| Trbovlje | 17.761 | 58km2 |
| Zagorje ob Savi | 17.167 | 147km2 |
| Zasavje | 45.226 | 264km2 |
| Slovenija | 2.025.886 | 20.273km2 |






