Thin films of (ZnO)(x)(CdO)(1-x) oxides were deposited on glass substrates by spray pyrolysis and annealed in air at 450 degreesC. The structural and optical properties of the as-grown and thermally annealed thin films are presented. The crystalline structure was studied by X-ray diffraction (XRD) having found the presence of the CdO cubic phase pattern for low Zn concentrations and a mixing of cubic-CdO and hexagonal-ZnO phases for low Cd concentrations. The crystallinity of all samples improves with the thermal annealing. The optical band-gap was also studied from the optical transmittance for the as-grown and annealed samples. As expected, the band-gap changes between that for pure CdO and that for ZnO.