For the first time, In2S3 films composed of nano-/microflakes were fabricated on fluorine-doped tin oxide (FTO) substrate using a simple and effective hydrothermal method. The structure, composition and morphology were examined by X-ray diffraction, energy-dispersive X-ray spectroscopy and field emission scanning electron microscopy. It was found that the reaction time, reaction temperature and the molar ratio of the reactants play key roles in controlling the final morphologies. The possible growth mechanism for the formation of In2S3 thin films was proposed. And the optical and photoelectrochemical properties were also investigated. In addition, In2O3 films were obtained by annealing the In2S3 precursor films in air at 500 degrees C. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.