Pure charcoal was impregnated with nickel and cobalt. The effect of metal impregnation on the thermal oxidation of charcoal was studied and compared by employing thermogravimetry and differential thermal analysis. The results show the impregnation of cobalt results in a signifcant decrease in the decomposition temperature of charcoal. The energies of activation for decomposition, calculated from the thermogravimetric curves, are 42.96, 38.61 and 30.58 kJ/mol for pure, nickel and cobalt impregnated charcoal respectively.