Decahedral Cu(2)WS(4) was synthesized by a facile hydrothermal method and employed as photocatalyst for photocatalytic hydrogen production for the first time. The hydrothermal method avoids the traditional use of H(2)S for the preparation of such chalcogenide, which guarantees an environmental-friendly process. The properties of the Cu(2)WS(4) samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis reflectance spectra, etc. The results showed that the decahedral Cu(2)WS(4) possessed a band gap of ca. 2.1ev. The photocatalyst was demonstrated to be very active under visible light for hydrogen production. Especially, Cu(2)WS(4) synthesized at 200 degrees C for 72 h showed the highest activity with the apparent quantum yield of 11% at 425 nm. The correlation between the preparation parameters and the photocatalytic properties were investigated. It was expected this first report of W-based chalcogenide photocatalyst would add to the photocatalyst group and lead to the finding of new photocatalyst with much higher activity. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.