The region of the Posavje hills is the smallest region in the country (264 km2) and has the lowest number of population. At the same time it ranks second in terms of population density.

The natural and geographic features of this region create conditions for industrial activities and a third of gross value added is still created by mining, quarrying and manufacturing. As these activities have a strong impact on the environment, in 2007 Zasavska invested the most of gross fixed capital formation for environmental protection compared to other regions.

In 2008, Zasavska was the only region with lower natural increase in comparison to the previous year. Since the natural decrease was accompanied by immigration, the number of population did not change a lot. The mean age of couples at marriage and the number of marriages per 1,000 population was in Zasavska the lowest in 2008. In the same year the registered unemployment rate was still among the three highest in the country; in 2008 it was almost twice as high as in the region with the lowest rate. Because of the lack of jobs a large share of the population commuted to work in other regions.

According to data on dwellings, Zasavska has the smallest dwellings both in terms of size and the number of rooms. According to the number of completed dwellings per 1,000 population, in 2008 Zasavska was the last among regions as not even one dwelling was completed.