The river rises northwest of city of Schwerin and the lake of Neumühler See near the Brüsewitz settlement of Eulenkrug and north of a hill ridge[2] at a height of about 49 m above sea level (NHN).

Continuing to head northwest, it collects the River Radegast in Börzow and the Maurine four kilometres (2.5 mi) before Dassow.

The length of the river from source to its mouth on the Dassower See is 52 kilometres (32 mi).

[1] The source region of the Stepenitz lies on the North Sea-Baltic Sea Watershed [de].

While the Stepenitz flows in a northwesterly direction via the Trave to the Baltic, the waters of the Sude, which rises just a few kilometres further southwest and heads in a southwesterly direction, run via the River Elbe to the North Sea.