Cadmium sulphide (CdS) and Cu doped CdS film were deposited onto commercially available FTO glass substrate by the hydrothermal assisted chemical bath deposition (HACBD). The effect of doping on the properties of CdS films were investigated. Optical, morphological, structural and photoluminescence properties of deposited films were investigated using UV–vis spectroscopy, SEM, FTIR, x-ray diffraction and photoluminescence spectroscopy (PL). Lower value of the bandgap energy was observed for the Cu doped CdS films as compared to those of the undoped CdS films. XRD patterns revealed a cubic and hexagonal crystal structure phase with (1 1 1) and (0 0 2) as the preferential orientation having an average crystallite size of 18 nm. SEM images revealed a change in the morphology of CdS and Cu-CdS thin films from spherical to disclike structures. PL spectra showed strong emission peak in visible region for both doped and undoped films. The associated chemical bonds were investigated using FTIR spectroscopy.