The source of the Shosha is in Zubtsovsky District of Tver Oblast, northwest of the selo of Knyazhyi Gory.

Downstream of the village of Novinki the Shosha enters the Ivankovo Reservoir, where it accepts two of its major tributaries, the Lama (right) and the Inyukha (left).

The Ivankovo Reservoir is crossed by the dam of the Moscow – Saint Petersburg Railway, and downstream of the dam the Volga enters from the left, at the former location of the mouth of the Shosha before the reservoir was filled in 1937.

The middle course of the Shosha, upstream of Kozlovo, is located in Zavidovo nature reserve, a closed area which is only accessible to high-level state employees.

The town of Volokolamsk and the urban-type settlements of Shakhovskaya, Lotoshino, Izoplit, Kozlovo, and Novozavidovsky lie in the drainage basin of the Shosha.