Abstract CdS films have been deposited on quartz substrate by means of pulsed laser deposition. The high quality of the deposited films is demonstrated by the presence of excitonic transition in the absorption spectra. The Elliot theory has been used to explain the absorption measurements and to obtain the fundamental energy gap value as a function of the temperature. Different from previous studies on CdS films, the temperature dependence of the band gap has been analyzed by taking into account the contribution of both the thermal dilatation and electron–phonon interaction. The photoluminescence emission is dominated by near band gap recombinations which persist up to room temperature.