The paper deals with the effect of modification with cobalt of a series of LaFe1-xCoxO3 mixed-oxide perovskites as catalyst precursors in the combined reforming of methane with CO2 and O-2 for the production of syngas. The perovskite type oxides were synthesized by fine chemical using the citrate sol-gel method and characterized by techniques such as FT-IR, BET surface area, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), TPR and inductively coupled plasma emission spectroscopy (ICP), under the condition of as-synthesized, reduced and used samples. The results showed that through this synthesis it is possible to obtain highly crystalline, homogeneous and pure solids, with well-defined structures. After reduction, the stabilization by the presence of iron of highly dispersed Co metallic particles from the cation on position B over the corresponding oxides was evidenced, decreasing deactivation by avoiding the sintering of metals and coke formation on the surface of the catalysts. The existence of strong Fe-Co interaction in the LaFe1-xCoxO3 with x = 0.4-0.6 produces a synergetic effect improving methane conversion and H-2 production. (c) 2005 Elsevier B.V. All rights reserved.