We have developed a method for the large-scale synthesis of gold nanoparticles (Au NPs) in an aqueous medium stabilized by various water-soluble ligands. Significantly, the narrow size-distribution of the particles is achieved without employing size-selective procedures. The versatility of the procedure is demonstrated for the preparation of three colloidal systems stabilized by different ligands. Transmission electron microscopy (TEM), zeta-potential measurements and UV-vis spectroscopy are used to characterize the three colloidal systems. (c) 2006 Elsevier Inc. All rights reserved.