A series of Pb/Ca catalysts, promoted with Li, K and La, and prepared by different procedures, have been examined for the oxidative coupling of methane. The Li promoted Pb/Ca had the highest C-2 selectivity and yield of the catalysts studied, including the unpromoted Pb/Ca. For the Li/Pb/Ca catalyst, CO2 added to the feed resulted in a decreased CH4 conversion and an increased C-2 selectivity. Addition of H2O to the feed with the same catalyst, increased C-2 yield. These effects are discussed in terms of deactivation and regeneration of the active sites by CO2 and H2O, respectively.