Perovskite-related oxide TmxCu3V4O 12 (space group Im3, Z = 2, a = 7.262-7.273 Å) with vacancies in the cationic sublattice has been prepared for the first time under barothermal conditions (p = 7.0-9.0 GPa, T = 900-1100°C). Electric resistivity (10-300 K) and magnetic susceptibility (0-300 K) were studied as a function of temperature. TmxCu3V4O12 is shown to have a metallic conductivity and paramagnetism. © Pleiades Publishing, Ltd., 2011.