This work presents a simple method to produce silver nanoparticles through AgNO3 chemical reduction in a continuous media. Aminosilanes act as catalytic reactors and superficial modifiers of Ag nanoparticles, inhibiting their growth and avoiding aggregation. Nanoparticles formation is studied by UV-vis spectroscopy, atomic force microscopy (AFM) and dynamic light scattering (DLS) techniques. The extent of the reduction reaction increases with either a higher aminosilane concentration or with aminosilanes with a higher number of amine groups. The number of amine groups in the aminosilane has also a strong effect on the size of the resulting Ag particles. The morphology of the Ag nanoparticles obtained is spherical and the mean size is of approximately 5 nm. (c) 2005 Elsevier B.V. All rights reserved.