Polycrystalline thin films of CuInSe 2 (CIS) were deposited by the electrochemical method. Some of the physical properties such as lattice parameters, crystal structure and X-ray data of CuInSe 2 (CIS) films with different Cu/In ratios (0.49-1.1) were determined using X-ray diffractometry. A structural transition from chalcopyrite to sphalerite was observed on the electrodeposited CuInSe 2 when the compositions of the thin films were varied from a quasi-stoichiometry to indium rich. The surface morphology with different Cu/In ratios was studied using a scanning electron microscope. Quasi-stoichiometric CuInSe 2 thin films were obtained in the chalcopyrite structure with grain sizes of the matter of 0.60 μm.