Conducting and transparent indium doped CdO thin films were prepared by spray pyrolysis on a glass substrate with various concentration of indium(2Â8 wt%) in the spray solution. The optical and structural properties of indiumdoped and undoped CdO films were studied utilizing optical transmission, X-ray diffraction and atomic forcemicroscope. X-ray analysis shows that the doped and undoped CdO films are preferentially orientated along (111) crystallographic directions. Increase of indium doping concentration increases the films packing density and reorient the crystallites along (1 1 1) plane. There is a decrease in the optical transmissions for all films with the decrease in wavelength. The light transmission of CdO films increases as In doping level increases. The optical band gap value of CdO was equal to 2.55 eV and it was increase with doping concentration and reaches a maximumvalue of 2.65 eV at 4 wt%indiumdoping. Low resistivity achieved in the present study was found to be 0.9×10- ³(Ù.cm) at 4wt%In doping.