CuAlO2 thin films have been grown on glass substrates using spray technique; a low-cost method of thin films depositing. The deposition was carried out in a 450–525°C range of substrate temperature. The solution and gas flow rates were kept constant at 5cm3min−1 and 6.10−3m3min−1, respectively. Compressed air was used as a carrier gas. The structural, morphological and optical properties of these thin films have been studied. These properties are strongly related to the substrate temperature and to the [Cu]/[Al] molar ratio r. X-ray diffraction analysis confirmed the initial amorphous nature of as-deposited films and phase transition into crystalline CuAlO2 with the preferential orientation (101) upon annealing at 570°C. The optical transmission of 80% has been achieved in the visible spectrum. CuAlO2 band gap energy in the range of 3.34–3.87eV has been found by optical measurement depending on fabrication parameters.