CdxZn1-xO films have been deposited by sol-gel spin-coating method onto glass substrates. The Cd/Zn ratio in solution was changed from 0 to 1. Zinc acetate dehydrates, cadmium acetate dehydrates, 2-methoxyethanol and monoethanolamine were used as a starting material (zinc and cadmium), solvent and stabilizer, respectively. The crystal structure and orientation of the films were investigated by X-ray diffraction (XRD) patterns. XRD patterns show that the films are polycrystalline nature. As x varies from 0 to 1, it was observed that the crystal structure changed from wurtzite (ZnO) to cubic (CdO) structure. The optical properties of these films have been investigated by means of the optical transmittance and reflectance spectra. A significant change in optical absorption edge, optical band gap and optical constant with variation in composition was observed. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.