Composite photocatalysts composed of TiO2 and ZrO2 have been prepared via the sol-gel method. The as-prepared nanocomposites are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis spectrometry and fluorescence emission spectra. The results shows that TiO2/ZrO2 nanocomposites are composed of mainly anatase titania and tetragonal ZrO2. Incorporating TiO2 particles with ZrO2 plays an important role in promoting the formation of nanoparticles with an anatase structure and leads to decreased fluorescence emission intensity. Most of the TiO2/ZrO2 nanocomposites exhibited comparable photocatalytic activity compared with commercial TiO2 for the degradation aqueous methyl orange (MO) under ultraviolet irradiation, while the composite with Zr/Ti mass ratio of 15.2% shows the highest photocatalytic performances. Furthermore, the as-prepared nanocomposites can be reused with little photocatalytic activity loss. Without any further treatment besides rinsing, the photocatalytic activity of TiO2/ZrO2 (15.2%) composites is still higher than after five-cycle utilization. (C) 2010 Elsevier B.V. All rights reserved.