Pure films of cadmium oxide and indium-doped cadmium oxide films were deposited using a spray pyrolysis technique. The deposited films were structurally characterised using the X-ray diffraction method. The structural studies revealed that films are polycrystalline in nature with a cubic lattice. The decrease in particle size from 42 nm to 34 nm was observed as dopant was introduced. For pure CdO thin films, the band gap energy obtained was of the order of 2.58 eV, and it decreased to 2.32 eV with the addition of dopant.