TiO2-SiO2 mixed gel spheres used for the sorption studies of cesium were prepared via sol-gel method. The source solutions used for the process were prepared from different mixtures of 1 M TiCl4 and 1 M Na2SiO3 solutions and converted into droplets in a gelation column. The suitable spheres for cesium adsorption were obtained using a methyl isobutyl ketone solution as the drop formation medium and ammonia as the gelling agent. The mixed oxide gels were identified and characterized by Analysis Adsorptive (N-2) DTA/TGA, FTIR and XRD analyses. The sorption behavior of Cs+ cations on TiO2-SiO2 mixed gel spheres has been studied as a function of TiO2 weight ratio, pH, time, cation concentration, temperature and competing ions. Sorption data have been interpreted in terms of Freundlich and Dubinin-Radushkevich equations. Sorption of Cs+ cations were found to be endothermic in nature with Delta H degrees (kJ/mol) of 5.06, and Delta S degrees (kJ/(mol K)) of 0.06. Negative Delta G degrees value obtained for Cs+ cations indicates the spontaneity of its sorption on mixed oxide gel spheres. (C) 2005 Elsevier B.V. All rights reserved.