Effect of nickel addition patterns on the catalytic performance of LaCoO3 for CO oxidation is investigated. A synergistic effect is induced between NiO and LaCoO3 for Ni/LaCoO3, leading to enhanced activity for CO oxidation. The impregnation of NiO improves both the reducibility and the amount of active sites of LaCoO3. The 10% Ni/LaCoO3 catalyst shows 100% CO conversion at 200 °C and no appreciable loss of activity is observed within 32 h.