A sonochemical method was applied to the preparation of monodispersed nanocrystalline PbSe in the presence of polyethylene glycol solvent. The nanocrytals were analyzed by X-ray diffraction (XRD), FT-IR, X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). It was found that the polyethylene glycol (PEG) as both a reducing agent and dispersant played an important role in the formation of monodispersed PbSe nanocrystals. (C) 2002 Elsevier Science B,V. All rights reserved.