In this study, CdO thin films were grown on glass substrates with SILAR technique at different thicknesses at room temperature. The thin films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV vis spectrophotometer. SEM images showed that the surface morphology of CdO thin films changed with the change in thickness. XRD results showed that all the samples had a cubic structure and the intensity of the peaks changed with the change in the number of cycles. Optical absorption measurements showed that the increase in thickness caused by the varied number of deposition cycles enlarged the band gap, and these values changed from 2.2 eV to 2.7 eV.