The river is 115 kilometres (71 mi) long and flows through the municipalities Åseral, Lyngdal, and Lindesnes.

Skjerka, Monn and Logna all flow into the lake Øre in Åseral which is considered the beginning of the main Mandalselva river.

The river passes through the villages of Kylland, Bjelland, Laudal, Heddeland, Øyslebø, and Krossen.

At present there are six power plants along the river and its upper tributaries: Logna, Smeland, Skjerka, Håverstad, Bjelland, and Laudal.

The highest stream flow in recent times were measured in October 1987, when it passed about 970 cubic metres per second (34,000 cu ft/s) at Kjølemoen in Holum.