Deposition of cerium on polycrystalline platinum ribbons has been studied by Auger electron spectroscopy. Our data indicate that intermixing or compound formation occurs during the deposition of Ce on Pt at room temperature. However, coadsorption of oxygen, at a low level, has been found to change the growth process, a pseudo layer-by-layer growth mechanism being then observed. The oxygen uptake has been followed on these various surfaces. It strongly decreases when a Pt-Ce compound is formed.