Tungsten oxysulfide thin films (WO y S z ) have been prepared by reactive radio-frequency magnetron sputtering using a WS2 target and a mixture of argon and oxygen gas. The composition, the texture and the structure depend on the sputtering parameters, such as the oxygen partial pressure and the total pressure (Ar+O2). For a total pressure of 1Pa, the range of the chemical composition is wide, from WS2 when no oxygen gas is introduced in the chamber, to WO3S0.02 when the oxygen partial pressure is equal to 10−2 Pa. Two amorphous thin films (WO1.05S2 and WO1.35S2.2) have given promising electrochemical performances as positive electrode in the cell: Li/LiAsF6, 1M EMC/WO y S z with a current density up to 37μA/cm2 between 1.6 and 3V.