Cadmium sulfide thin films have been deposited by electrodeposition using the potentiostatic method on indium tin oxide (ITO)-coated glass substrates from aqueous solution containing CdCl2 . 2H(2)O and Na2S2O3 at 90 degrees C. The depositions were carried out for various cathodic potentials. Good quality films were obtained at a cathodic potential of -0.6 V. Voltammograms have been recorded to optimize the co-deposition region of CdS on ITO-coated glass substrates at 90 degrees C. The structural and optical characterisations have been carried out using an X-ray diffractometer and UV-Vis spectrophotometry. Annealing the samples at 350 degrees C in H-2 for 30 min resulted in increase in intensity as well as a shift towards lower scattering angles due to the lattice parameter increase from enlarged CdS cell. A bandgap narrowing was also observed as a consequence of annealing.