Recently, a huge variety of physical and chemical synthetic processes have been reported to prepare nanostructured materials made of very small (diameter < 50 nm) metallic clusters. Depending on the nature of clusters, this new kind of materials posses interesting properties (electronic, optical, magnetic, catalytic) that can be tailored as a function of the particles size and shape. Silver nanoparticles have been obtained by direct thermal treatment or by beam-enhanced decomposition (ion, electron and laser) of a silver organometallic compound (precursor) spinned onto suitable substrates. In this paper, we present the results of a study on the size distribution of such nanoparticles as a function of the different synthesis methods. It was found that the methods employed strongly affect the silver nanoparticles formation. Smaller silver nanoclusters; were obtained after reduction by ion beam irradiation and thermal treatment, as observed by using different techniques (AFM, XRD and UV-Vis). (C) 2003 Published by Elsevier B.V.