CeF3, CeF3:Tb, and CeF3:Tb/LaF3 (core/shell) nanoparticles were prepared by the polyol method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), UV -vis absorption spectra, photoluminescence (PL) spectra, and lifetimes. The results of XRD indicate that the obtained CeF 3, CeF3:Tb, and CeF3:Tb/LaF3 (core/shell) nanoparticles crystallized well at 200 °C in diethylene glycol (DEG) with a hexagonal structure. The TEM images illustrate that the CeF 3 and CeF3:Tb nanoparticles are spherical with a mean diameter of 7 nm. The growth of the LaF 3 shell around the CeF 3:Tb core nanoparticles resulted in an increase of the average size (11 nm) of the nanopaticles as well as in a broadening of their size distribution. These nanocrystals can be well-dispersed in ethanol to form clear colloidal solutions. The colloidal solutions of CeF3 and CeF3:Tb show the characteristic emission of Ce 3+ 5d-4f (320 nm) and Tb 3+ D4-FJ (J ) 6-3, with D4-F5 green emission at 542 nm as the strongest one) transitions, respectively. The emission intensity and lifetime of the CeF 3:Tb/LaF3 (core/shell) nanoparticles increased with respect to those of CeF3:Tb core particles. This indicates that a significant amount of nonradiative centers existing on the surface of CeF 3:Tb nanoparticles can be eliminated by the shielding effect of LaF 3 shells. Finally, the energy transfer from Ce 3+ to Tb3+ was investigated in CeF 3:Tb nanoparticles in detail.