Photoluminescence (PL) and transmittance measurements were carried out to investigate the optical properties of ZnO nanoparticles inserted into ultraviolet (UV) opal. The ZnO nanoparticles were grown in the voids between face-centered cubic packed silica spheres by using a chemical deposition. The PL spectra showed a decrease in the band edge emission and an enhancement of the deep-level emission from the ZnO nanoparticles embedded in the UV opal. The PL intensity enhancement in the green spectral region might be attributed to the Purcell effect. The infiltration of ZnO nanoparticles inside an artificial opal can be used to select the spectral band and to increase the emission efficiency of ZnO nalloparticles. (c) 2005 Elsevier B.V. All rights reserved.