Undoped and Na-doped lead oxides supported on alpha-Al2O3 were used in the oxidative coupling of methane (OCM) by cofeeding methane and oxygen at atmospheric pressure. In general, the methane conversion increased with increasing Pb-loading but the C2+ selectivity decreased slightly. Another major effect observed on incorporation of PbO into alpha-Al2O3 was the dramatic increase of carbon dioxide with lead content. The combined use of X-ray diffraction, temperature-programmed reduction and photoelectron spectroscopy revealed that a certain proportion of Pb4+ species is present in the undoped catalysts, and this is greater for the catalysts with higher lead oxide content. These techniques also revealed that lead oxide is partially evaporated under severe conditions imposed by the OCM, although the evaporation can be diminished by doping with sodium. The beneficial effect of sodium on the catalyst stability is also accompanied by a better catalyst performance due to the ability of sodium oxide to activate methane.