Multiphase nanowires composed of Cu3Ge, GeOx, and CuGeO3, obtained through the thermochemical reduction of CuGeO3, are investigated as anode materials for lithium-ion batteries. Initially, CuGeO3 nanowires are prepared by using a facile hydrothermal process without the use of any templates or surfactants. The as-prepared CuGeO3 nanowires are demonstrated to be single-crystalline with a diameter of around 70 nm and a length of 0.5–2 μm. Subsequently, multiphase Cu3Ge/GeOx/CuGeO3 nanowires are prepared through the controlled thermochemical reduction of the as-prepared CuGeO3 nanowires under a H2 atmosphere at 250 °C. Upon thermochemical reduction, the wire-shaped morphology is retained, but the phase partially transforms to a mixture of crystalline Cu3Ge nano-domains (<10 nm) with high electronic conductivity and amorphous GeOx. The newly generated multiphase nanowires exhibit enhanced cycle stability with high lithium-storage capability compared to that of the as-prepared CuGeO3 nanowires.