The fauna of the rivers of the north of Western Siberia that do not belong to the Ob' River basin is of particular interest from the point of view of zoogeography and understanding of the processes of formation of the freshwater malacofauna. Starting in the taiga zone, these rivers flow north and cannot serve as a way of interzonal dispersal of species from lower latitudes. However, information about the fresh-water malacofauna of these river basins is poorly presented in the scientific literature, some of the published species findings are doubtful or erroneous. The gastropod mollusks of the family Valvatidae of the Taz river basin (Western Siberia) are considered. The basin is located closer to the Yenisei than to the Ob' River basin. The study was based on original authors' material represented by both qualitative and quantitative samples. It has been found that eight species of mollusks of the genus Valvata occurs in the water reservoirs and streams of the Taz basin, an annotated list of species is presented, and a brief zoogeographic characteristic is given. Three species (Valvata helicoidea, V. sorensis and V. korotnevi) are for the first time recorded from the basin, one of them (V. korotnevi) is for the first time recorded from the Western Siberia waterbodies.