Nano-structured Ce1-xFexO2 mixed oxides with different Fe loading have been synthesized via co-precipitation route and were evaluated as heterogeneous catalysts for catalytic wet air oxidation of wastewater. The synthesized catalysts were characterized by XRD, FT-IR, TGA, N-2 adsorption/desorption, FE-SEM, TEM and EDS. The influence of initial pH, reaction temperature, reaction time and catalyst dose has been evaluated for the removal of COD and color from paper industry wastewater. The catalytic performance of Ce1-xFexO2 mixed oxides was found to be superior to those of individual oxides of Ce and Fe. The molar ratio of Ce/Fe markedly influenced the activity of mixed oxides. Ce0.4Fe0.6O2 mixed oxide exhibited maximum COD (74%) and color (82%) removal under optimum experimental conditions. The biodegradability of wastewater increased from an initial level of 0.27-0.47 after treatment. The highest catalytic activity of Ce0.4Fe0.6O2 mixed oxide was strongly influenced by its high surface area, high pore volume, small particle size and high dispersion of Fe2O3 into ceria lattice. (C) 2015 Elsevier B.V. All rights reserved.