Anisothermal and isothermal oxidation tests have been used to establish correlations between growth kinetics, morphological and microstructural evolutions of NiO layers formed during the oxidation of high purity nickel. It is shown that the transport phenomena taking place during the growth of such layers are complex and a growth model is proposed, which takes into account the diffusion of cationic species (in volume and by short-circuits), the transport of oxygen and the interfacial reactions.