[Bis(2-hydroxy-1-naphthaldehydato) copper(II)] complex, as a novel precursor, was employed in thermal decomposition process to synthesize metallic copper nanoparticles using oleylamine (C18H37N) as capping agent. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible (UV-vis) spectroscopy. The synthesized copper nanoparticles have a fcc structure with average size 20-35 nm. (C) 2010 Elsevier B. V. All rights reserved.