Catalysts of the type CuO/Al2O3, NiO/Al2O3 and Co3O4/Al2O3 with different chemical compositions and subjected to different calcination temperatures were prepared using the impregnation technique. The crystal structure of the calcination products was determined by X-ray diffraction (XRD) while the textural properties were determined from nitrogen adsorption at 77 K. The activity of the catalysts towards the oxidation of carbon monoxide with O2 at different temperatures was also investigated. XRD indicated that calcination of these systems at ≤1073 K did not lead to the formation of spinel. Moreover, no characteristic lines indicating the existence of any metal oxide were observed when the concentration of the latter was less than 10 mol%. The catalytic oxidation of CO followed first-order kinetics with the catalytic activity depending on the metal oxide loading and its dispersion on the surface of the alumina. In most cases, Co3O4/Al2O3 catalysts exhibited the highest activity.