This study was carried out by the streams of Tunceli province (Turkey) between June 2008 and May 2009 to determine Mollusca fauna. Samples were taken at 20 stations, seasonally. Mollusca fauna of the streams of Tunceli was represented by three species of Prosobranchia (Bithynia pseudemmericia, Bithynia tentaculata, Anadoludamnicola gloeri), four species of Pulmonata (Galba truncatula, Radix labiata, Physella acuta, Acroloxus lacustris), and two species of Bivalvia (Pisidium casertanum, Pisidium lilljeborgii). Canonical Correspondence Analysis (CCA) was applied to determine the relationships among the Mollusca fauna and physicochemical variables. CCA explained 31.897% of the species and environmental variation by the second axis. Water temperature (T), dissolved oxygen (DO), pH, and Ca+2 were the most influential variables on the Mollusca fauna. The present study is the first research on the Mollusca fauna in the streams of Tunceli province. Molluscs species were recorded for the first time from the area.