TiO2 hydrosols were obtained by dispersing nanoparticles synthesized from titanium ethoxide as precursor via reflux method without any further thermal treatment. In this study, the reaction parameters such as solvent, type of catalyst, temperature and duration of the synthesis of TiO2 nanoparticles were extensively investigated. The crystalline nanoparticles obtained without calcination have particle size in range of 3.3 nm and 5 nm, and BET surface area of up to 182 m(2)/g. Transparent TiO2 hydrosols were prepared in both water and non-polar solvent without use of any additional dispersing agent. The synthesized nanoparticles exhibited photocatalytic activity against Rhodamine B dye. (C) 2012 Elsevier B.V. All rights reserved.