Quaternary Ag-Zn-Sn-S thin films were deposited onto the surface of indium-tin-oxide-coated glass substrates using chemical bath deposition. The procedures for the growth of Ag-Zn-Sn-S semiconductor films are presented. The optical, physical and photoelectrochemical performances of the samples were investigated. The X-ray diffraction patterns of the samples reveal that tetragonal Ag2ZnSnS4 phase with small amount of impurities, such as Ag8SnS6, can be obtained using 0.4 M ethylenediaminetetraacetic acid disodium salt dihydrate as the chelating agent and deposition temperature kept at 70 degrees C. The major phase of other samples prepared in this study was the Ag8SnS6 phase. The energy band gaps of the samples are in the range of 2.08 to 2.56 eV, depending on the compositions. The maximum photoelectrochemical performance of samples in this study was 0.65 mA cm(-2) at an external potential of + 1.0 V vs. an Ag/AgCl electrode in aqueous K2SO3 and Na2S solution at an irradiation of 100 mW cm(-2), using a Xe lamp as the light source. Crown Copyright (C) 2014 Published by Elsevier B. V. All rights reserved.