An ultrafine-grained (UFG) Ni 3 Al was fabricated by annealing an electrodeposited Ni–Al composite in vacuum at 600°C for 2h. The UFG Ni 3 Al, compared to a compositional-similar but coarse-grained (CG) alloy prepared by arc-melting, exhibited a greatly increased cyclic oxidation resistance at 900°C. Microstructural investigation showed that the CG alloy grew a scale with a high susceptibility to buckling and cracking because of the formation of large voids at the scale/metal interface, but that the UFG alloy grew an adherent scale, because its typical structure prevented the formation of the interface void during oxidation.