Cadmium telluride oxide CdTeO3 thin films were prepared by r.f.-sputtering from a polycrystalline CdTe target in an atmosphere of nitrogen and oxygen. X-ray diffraction (XRD) analysis showed that the as-deposited samples were amorphous. X-ray photoelectron spectroscopy (XPS) measurements revealed that the films were nearly stoichiometric. The resistivity and the static dielectric constant of the as-deposited layers were found to be 3 X 10(6) Omega m and 16, respectively. Optical transmission measurements in the ultraviolet-visible-near-IR (UV-VIS-NTR) region allowed the determination of the optical constants of the prepared films. Post-deposition annealing of the layers at 420 degrees C for 2 h favored their crystallization. Finally, we show that polycrystalline CdTO3 films can be grown on CdTe films, deposited on C7059 glass by an appropriate heat-treatment of the CdTeO3/CdTe/C7059 structure.