The size-controlled immobilization of silver nanoparticles onto the silica surface was carried out through one-pot process involving polyol process for the first time. Thiol groups were employed as a chemical protocol to make a binding bridge between silver nanoparticle and silica surface. The size of immobilized silver nanoparticles was controlled by reaction temperature and time at two different concentrations of silver nitrate: 1000 and 10,000 ppm. This one-pot process involving polyol process can simplify the conventional complex reaction process to control the size of immobilized metal nanoparticles. Also, this research can contribute to the immobilization of the other metals onto the inorganic supports and to the control of the size of immobilized metal particles. (C) 2006 Elsevier Ltd. All rights reserved.