In this paper, photoelectrochemical cell has been developed using indium tin oxide (ITO) as the substrate of the CuIn5S8 photoanode and Pt as the cathode. The photoresponse measurements have been conducted in neutral Na2SO4 aqueous electrolyte solutions in three-electrode system and under irradiation of 100 mWcm(-2). We have found that the [Cu]/[In] molar ratio has strongly influenced the current voltage (J-V) response. The highest photocurrent density of ca. 8 mA/cm(2) with an applied potential of 0.25 V vs. Ag/AgCl has been observed for sample deposited from the molar ratio of ([Cu]/[In] = 0.28). The results show that ternary n-CuIn5S8 thin film electrodes have potential in photocatalytic water splitting application. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.