Cu-Mn spinel oxides with a high specific surface area were prepared by a simple and waste-free soft reactive grinding (SRG) technique involving the use of clean precursor salts as the starting materials. The samples were characterized by means of N-2 adsorption, X-ray diffraction (XRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed reduction (H-2-TPR). The results show that the catalysts obtained from the SRG route exhibited much higher catalytic activity in methanol steam reforming as compared to their wet-chemically synthesized counterparts prepared by conventional coprecipitation. The superior performance of the SRG-derived Cu-Mn materials was attributed to the favorable formation of Cu1.5Mn1.5O4 spinel phase leading to the creation of much smaller copper nanoparticles with enhanced stability in the working catalyst.