ZnS nanoparticles about 3 nm in size were prepared by a simple, rapid and reliable route under microwave irradiation in a heterogeneous system, using ZnAc2.2H(2)O (Ac=CH3COO) and Na(2)S(.)9H(2)O as the starting materials, ethylene glycol (EG) as the medium. The product was characterized with X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and ED, respectively: The optical properties of ZnS nanoparticles were studied. (C) 2004 Elsevier Ltd. All rights reserved.