In this work, zinc oxide (ZnO) precursor was prepared by precipitation method from zinc nitrate and ammonium carbonate in aqueous solutions. ZnO nanoparticles were synthesized by annealing the precursor at different temperatures. The effect of the annealing temperature on the particle size and photo-luminescence (PL) properties of the synthesized ZnO nanoparticles were studied by XRD, SEM, BET, TG-DTA and PL measurements. The XRD results indicated that the synthesized ZnO nanoparticles had the pure wurtzite structure. It is found that with increasing the annealing temperature the crystalinity and particle size increases as well as the lattice parameters approaches to those of the XRD standard. The studies of the aggregation of the samples were also carried out by comparing SEM micrographs with specific surface measurements and XRD results. Finally, the room temperature PL spectra show UV emission peak in the range of 378.50-379.80 nm, which is close to the bulk ZnO. (C) 2012 Elsevier Ltd. All rights reserved.