Catalysts were prepared from hydrotalcite precursors, then characterized and tested for methane steam reforming. The precursors were synthesized by the traditional technique, based on co-precipitation of Co, Mg and Al nitrates with carbonate; by co-precipitation of Mg and Al nitrates with pre-synthesized cobalt chelate and by anion-exchange of hydrotalcite NO3- with cobalt chelate. The oxides were analyzed by atomic absorption spectrophotometry, thermogravimetric analysis, X-ray diffraction, temperature programmed reduction with H-2, catalytic tests and elemental analysis. The catalysts, tested in methane steam reforming, showed stability and activity at a feed molar ratio H2O:CH4 = 2:1. (c) 2005 Elsevier B.V. All rights reserved.