CeO2/YSZ nanocomposite powders, characterized by increasing Ce/Zr atomic ratio, were obtained by depositing, by wet impregnation, different amounts of CeO2 on the yttria-stabilized zirconia (YSZ) surface. These powders were characterized by means of X-ray photoelectron spectroscopy, transmission electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Experimental results allow us to obtain interesting information concerning the growth mode, the morphology. and the dimensions of the CeO2 clusters on the YSZ supporting surface. A 3-D growing mechanism was observed for the CeO2 nanoparticles. With increasing Ce/Zr atomic ratio the CeO-, clusters become more and more spherical. Moreover, XPS data also show the presence of Ce(III) and Ce(IV) ions at the interface supported/supporting oxides.