Ni/Al2O3 catalysts promoted with alkaline earth (Mg and Ca) or lanthanide (La and Ce) oxides were prepared by co-impregnation or consecutive impregnation of nickel and promoter on gamma-Al2O3 varying order. The reaction of reforming CH4 with CO2 was studied between 650 and 850 degrees C at atmospheric pressure over these catalysts. It was found that both alkaline earth and lanthanide oxides exerted a promotion effect on the initial activity, but they likely behaved in different ways since the catalysts promoted with alkaline earth oxides were much more sensitive to the impregnation order of nickel than those promoted with lanthanide oxides.