Thin films of cerium dioxide (CeO2) were prepared on glass substrates by the spray pyrolysis process using an aqueous solution of CeCl3,7H(2)O or Ce(NO3)(3). The structure, surface morphology chemical composition and optical properties of these films were investigated. X-Ray diffraction and Raman spectroscopy showed that the obtained films were polycrystalline with a cubic fluorite structure and were strongly oriented along the (100) direction. The surface morphology of the films was found to depend strongly on the initial solutions. Thus, two types of surface texture with large difference in the grain size and porosity were obtained by using chloride or nitrate solution. On the other hand, all these films showed high transparency, more than 80% in the visible and near-infrared region. The composition of these films was also examined by both X-ray photoelectron spectroscopy and electron probe microanalysis.