We have synthesized hexagonal phase of CuS nanocrystals by developing a composite-surfactants-assisted-solvothermal (CSS) route. X-ray powder diffraction (XRD) analyses showed that Cu:S mole ratio had a great influence on the phase purity of the products. Transmission electronic microscopy (TEM) revealed that the diameter of the product was in a range of 8-10 nm. The formation of the product might be through an in situ reduction-sulfidation mechanism where divalent copper ions reduce to metallic Cu before sufidation to CuS based on the contrast experiments. The present route would provide a general strategy to metal sulfide nanocrystals. (C) 2007 Elsevier B.V. All rights reserved.