A kind of Nd3+-doped LaF3 nanoparticles with core/shell structure were synthesized via a co-precipitation method. The possible formation mechanisms for the core/shell architectures were presented. The X-ray diffraction (XRD) patterns indicated that the obtained nanoparticles exhibit hexagonal structure. In comparison with LaF3:Nd core nanoparticles, the fluorescence intensity and lifetime were increased by 140% and 150% respectively in LaF3:Nd/LaF3 core/shell nanoparticles. The obvious features are mainly attributed to the formation of LaF3 shell which effectively protected the Nd3+ ions from surrounding influence. The results show that rare-earth-doped nanoparticles with core/shell structure have potential applications in biological labeling and light-emitting devices. (C) 2010 Elsevier B.V. All rights reserved.