A novel total decomposition of N2O was performed on the nano-sized particles of substituted CoxFe3-xO4 magnetite (with x=0-1). The given results showed that the partial incorporation of Fe2+ by Co2+ into Fe3O4 spinel substrate led to a significant amelioration in the catalytic activity for the N2O catalytic reaction. Furthermore, the catalytic activity of prepared substances depended on the Fe2+ substitution amount by Co2+ cation. The N2O conversion achieved 100% over the nano-sized Co0.6Fe2.4O4 catalyst at 255, 285 and 291 degrees C for pure N2O, N2O with the presence of oxygen and N2O in the presence of water steam, respectively. A relative increasing of decomposition temperatures was observed after O-2 addition. Moreover, the characterization of all samples showed that the catalyst surfaces contain nano-size particles accompanied by well distribution. (C) 2012 Elsevier B.V. All rights reserved.