An innovative synthesis of inorganic fullerene-like disulfide tungsten (IF-WS2) nanoparticles was developed using a chemical reduction reaction in a horizontal quartz reactor. In this process, first tungsten trisulfide (WS3) was formed via a chemical reaction of tetra thiotungstate ammonium ((NH4)(2)WS4), polyethylene glycol (PEG), and hydrochloric acid (HCl) at ambient temperature and pressure. Subsequently, WS3 was reacted with hydrogen (H-2) at high temperature (1173-1373 K) in a quartz tube. The produced WS2 nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDAX), and transmission electron microscopy (TEM). The characterization results indicated that the high-purity (100%) IF-WS2 nanoparticles were produced. Moreover, addition of surfactant (PEG) and higher operating temperature (1173-1373 K) decreased the particles agglomeration, and consequently led to the reduction of average diameter of WS2 particles in the range of 50-78 nm. The developed method is simple, environmentally compatible, and cost-effective in contrast to the conventional techniques. (C) 2010 Elsevier Ltd. All rights reserved.