On July 1st. 1885 the municipality of Eker was split into two, Nedre (Lower) Eiker and Øvre (Upper) Eiker municipalities. Nedre Eiker was the industry part of the old municipality of Eker while Øvre Eiker was the farming part. This area was among the first in Norway to be industrialized and the export of oak timber was the start. Further along the way we have had pottery factories, cotton mill, rubber factories and paper mills in our municipality.

Today the only remaining large factory is Trelleborg Offshore Norway. This factory is a major supplier to the oil industry.

All the paper mills closed in the late 60-ties early 70-ies and this left the municipality with challenges since quite a few did not get other employment.

Nedre Eiker has developed into a regional shopping centre. The main shopping area has moved from Mjøndalen to Buskerud Storsenter in Krokstadelva. In the administrative centre of Mjøndalen we find more traditional shops as independent clothes shops, furniture shops and bakeries.

Norway's largest trading house for inner and outer beauty and wellbeing, Validus Engros, is established on the relatively new industrial area in Mjøndalen, Orkidehøgda.

The poet Herman Wildenvey was born in Portåsen, Mjøndalen in 1885 and his birthplace is one of our cultural core areas in Nedre Eiker.

Nedre Eiker has lots of limestone in its grounds and this is the reason why our municipality is the record holder of 24 orchids of the 37 that are found in Norway.