The effect of mechanochemical treatment on the hydrogenation of CO and CO2 was studied using a flow milling vial as a catalytic reactor. Traditional catalysts for the methane formation (Ni, Zr, Zr-Ni-containing samples, Zr hydride and Zr-Ni hydrides of various genesis), as well as inactive NiO and ZrO2, were examined. The following features of the mechanically driven CO hydrogenation were observed : (i) Zr and Zr-Ni hydrides demonstrated the highest activity in the formation of CH4; (ii) the hydrogen present in the reaction mixture suppressed the formation of CH4; (iii) Ni was found to be ineffective in the formation of CH4 but active in the reaction of CO disproportionation; (iv) on the oxide samples, a small amount of CH4 was formed owing to the mechanical activation. Deep structural transformations of the metal and hydride samples under milling in the reaction mixture were found to be responsible for the changes in their catalytic activity. Only zirconium hydride exhibited catalytic activity for CO2 hydrogenation. In this case, no phase transformation was observed.