A series of NiO/CeO2 catalysts were prepared by using the combustion method and characterized by using XRD, N2-physisorption, TEM, UV-visible, Raman, XPS, ICP-OES and H2-TPR. Typical results indicated the NiO/CeO2 had a better performance than CeO2 for CO oxidation and 15 wt% NiO/CeO2 is active and stable, whereas catalysts with a higher NiO content of 20 and 30 wt% deactivated at 130 °C onwards. The high activity and excellent stability of 15% NiO/CeO2 catalysts can be ascribed to their high oxygen vacancy, high dispersion of NiO and strong metal-support interaction that leads to synergy between NiO and CeO2. © 2013 The Royal Society of Chemistry.