The effect of Y+Zr+Hf and La+Ce on the oxidation behavior of FeCrAl alloys was tested at 1373 K in laboratory air under atmospheric pressure. Oxidation tests performed under different oxygen isotope atmospheres indicated that after 8 h of oxidation, the mixed diffusion of oxygen and aluminum controlled the alumina scale growth. After 96 h of oxidation, the oxide scale mainly grew via oxygen diffusion. The chemical analyses of the alumina scales allowed location of the reactive elements at the alumina grain boundaries and at the metal-oxide interface after the longer oxidation tests, but never after the shorter tests. These results are discussed in relation with the transient oxidation stage necessary for incorporation of the reactive elements into the growing oxide scale.