Calcium tungstate CaWO4 nanoparticles doped with Tb3+ of 20 nm in average size were prepared by sonochemical method. The crystallites were immobilized in a silica matrix by the sol gel method. The matrix in the CaWO4:Tb3+@SiO2 composite material plays two roles. First of all it provides a good coverage of the nanoparticle defected surface and it prevents the nanoparticles from agglomeration. The nanoparticles capped with silica are characterized by energy transfer from WO42- group to Tb3+ thus enabling luminescence enhancement of the latter ions. The composite luminescent material was analyzed by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), selected area electron diffraction (SAED) and luminescence techniques. CaWO4:Tb3+@SiO2 exhibits higher emission intensity than CaWO4:Tb3+ in the nanopowder form. 0 2014 Elsevier B.V. All rights reserved.