SiO2 thin films co-doped with ZnO nanoparticles and Eu3+ ions were prepared by sol-gel method. The formation of nano-sized ZnO particles was confirmed by X-ray diffraction patterns and transmission electron microscopy. The characteristic emission bands from Eu3+ ions can be observed at room temperature and the luminescence intensity is increased obviously by introducing ZnO nanoparticles into Eu3+-doped silica films. The integrated luminescence intensity is influenced by the concentration and size of ZnO particles, suggesting effective energy transfer from nano-sized ZnO to Eu3+ ions. It is argued that the efficient luminescence enhancement occurs under the suitable Zn2+ amount and annealing temperature. (C) 2012 Elsevier B.V. All rights reserved.