The Weißache flows in the Sölllandl, a valley between the Kaiser Mountains and the Hohe Salve.

It rises at about 1,600 m (AA) on the Zinsberggrund in the Weißachergraben and discharges in Endach [de], a district of Kufstein, into the Inn.

The Ache flows through the following municipalities (in downstream order): Ellmau, Scheffau, Söll, Schwoich, Kufstein.

Before the road Eibergstraße [de] branches off to Schwoich, the river is divided and a larger part is pumped under the hill Kufsteiner Waldt into a heat-only boiler station south of Kufsteins and acts as cooling water, before it flows back on a natural course into the Inn.

Between Egerbach (a district of Schwoich) and Endach [de] (a district of Kufstein) the remaining part of the Weißache flows for about 800 m (2,600 ft) through a long gully, before it exits from the valley and heads northwest towards the Inn.