The valley is drained by the Poschiavino river, flowing through Lago di Poschiavo. Smaller lakes in its basin include Lago Bianco, Lago di Saoseo, and Lago di Val Viola. From north to south, the valley descends from an altitude of to , passing through different altitudinal zones. The surrounding mountains of the Bernina Range and the Livigno Alps include the Piz Palü, , Piz Cambrena, , Piz Varuna, , and Piz Lagalb, .