We report the first synthesis of ultrafine zinc sulfide (ZnS) nanowires with a sphalerite structure. Large-area, high-and uniform-density ZnS nanowires were grown on Au-coated silicon substrates by hydrogen-assisted thermal evaporation. The product was analyzed with scanning electron microscopy, X-ray diffraction, transmission electron microscopy and photoluminescence (PL). The ZnS nanowires had a sphalerite structure, a growth direction along [111], diameters of 10-20 nm, and lengths of several micrometers. The PL spectrum of the ZnS nanowires was measured. The growth of the ZnS nanowires was explained with the vapor-liquid-solid model, and their structure could be controlled by the deposition temperature. (C) 2003 Published by Elsevier B.V.