The effect of the calcination temperature on manganese-based catalysts used in the complete oxidation of acetone has been studied. The catalysts, containing manganese and samarium and being in bulk oxide form, were prepared in the laboratory and calcined at 673, 823, 1073 and 1273 K. The calcination temperature controls and modifies the type of single manganese oxide present, the development of the perovskite structure of samarium-manganese oxides, and the specific surface area of these materials. A positive effect on the catalyst performance has been observed for the samarium-manganese oxides with respect to the single manganese ones. (C) 2004 Elsevier B.V. All rights reserved.