Bifunctional magnetic-luminescent nanocomposites with Fe3O4 nanoparticles as the cores and YF3:Ce3+,Tb3+ as the shells were synthesized by a facile direct precipitation method. Transmission electron microscopy (TEM) images revealed that the obtained bifunctional nanocomposites had a core-shell structure, in a spherical shape with a size ranging from 160 to 220 nm, and the shell thickness of about 25 nm. The X-ray diffraction (XRD) patterns showed that a cubic spinel structure of Fe3O4 core and an orthogonal phase of YF3 shell were obtained. Photoluminescence (PL) spectra confirmed that the nanocomposites displayed a strong green light emission. Magnetic measurements indicated that the obtained bifunctional nanocomposites exhibited a stronger magnetic behavior at room temperature. Therefore, the bifunctional nanocomposites are expected to develop many potential applications in biomedical fields. (C) 2011 Elsevier B.V. All rights reserved.