Synthesis of nanoparticles by green route is an emerging technique drawing more attention recently because of several advantages over the convention chemical routes. The present study reports one-pot synthesis and in situ stabilization of silver nanoparticles using Aegle marmelos leaf extract. Nanoparticles of almost uniform spherical size (similar to 60 nm) were synthesized within similar to 25 min reaction time at room temperature. The size of particles depends on the ratio of AgNO3 and leaf extract. The crystallinity, size, and shape of the nanoparticles were characterized by X-ray diffraction, dynamic light scattering, and scanning electron microscopy respectively. The size stability was attained by the capping effect of polyphenolic tannin compound, procatacheuate in the extract. The capped polyphenols can be removed from the particle surface by simple NaH/methanol wash. The involvement of phenolic compounds in metal ion reduction and capping were supported by UV-visible spectroscopy, infrared spectroscopy, high performance liquid chromatography, and zeta potential measurements. (C) 2012 Elsevier Ltd. All rights reserved.