The reduction of metal oxides is usually carried out at high temperature in appropriate conditions with respect to equilibrium thermodynamics. However using the high activity of fresh surfaces enables mechanically activated reduction. After ball-milling of silver oxide, Ag2O, copper oxide, CuO, and hematite, Fe2O3, respectively, with carbon powder, metallic silver and copper could be obtained at room temperature and hematite was reduced to magnetite. The reduction processes were investigated by X-ray diffraction and Fe-57 Mossbauer spectroscopy.