Thin films of ZnIn2S4 were deposited onto indium-doped tin oxide (ITO)-coated glass substrates from a mixed aqueous solution of ZnCl2, InCl3 and (NH2)(2)CS by a simple and economical spray pyrolysis technique. Structural, morphologic and optical properties of the deposited films were characterized by XRD, SEM, and UV-vis spectra. Moreover, the electrochemical and photoelectrochemical properties were studied via Mott-Schottky method, current-voltage measurement, and photocurrent spectrum measurement. It was found that ZnIn2S4 films can be prepared by spray pyrolysis and the grain size obtained was about 120-200 nm in diameter. The deposited films have a cubic spinel structure and the optical band gap is about 2.1 eV The results of electrochemical and photoelectrochemical characteristics show that ZnIn2S4 is a potential material for splitting water to produce hydrogen using solar energy. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.