We are reporting a novel, low-cost and eco-friendly route for rapid synthesis of lead nanoparticles by using 0.5% aqueous extract of Jatropha curcas L latex. Lead nanoparticles were characterized initially by UV-vis spectroscopy and shown distinct peak at 218 nm. This peak was highly specific for lead nanoparticles. Formation of Pb (0) was confirmed by X-ray diffraction technique (XRD).Transmission electron microscopy (TEM) was performed for estimating the size and shape of nanoparticles. The average size of lead nanoparticles was found to be in the range of 10 to 12.5 nm. Energy dispersive analysis of X-rays (EDAX) showed distinct peaks of lead. Fourier Transform Infrared Spectroscopy (FTIR) were performed to find the role of cyclic peptides namely curcacycline A (an octapeptide) and curcacycline B (a nonapeptide) as a possible reducing and capping agents present in the latex of Jatropha curcas L. Lead nanoparticles formed by the above method were monodisperse. (C) 2011 Elsevier B.V. All rights reserved.