Bismuth telluride-based materials have been widely investigated due to their applications for the development of high-performance thermoelectric devices. Here, we numerically determine the effective electrical conductivity (σeff), thermal conductivity (keff), and Seebeck coefficient (Seff) of composite materials made up of VO 2 nanoparticles embedded in a Bi 0.5Sb 1.5Te 3 (BST) matrix. The temperature evolution of these three properties along with the thermoelectric figure of merit (ZT=σeffSeff2T/keff) is analyzed across the metal–insulator transition of VO 2 and for temperatures up to 550 K. For temperatures higher than 350 K, it is shown that VO 2 nanoparticles with a concentration of 34 % enhance the electrical conductivity and ZT of the matrix by about 16 % and 10 %, respectively, while the Seebeck coefficient remains pretty much constant. This indicates that VO 2 nanoparticles provide an effective way to enhance the thermoelectric efficiency of Bi 0.5Sb 1.5Te 3 materials. The calculated ZT values for VO 2 are in good agreement with the experimental data reported in the literature for temperatures higher than 350 K. The thermal conductivity values obtained for VO 2 in the insulating phase are in good agreement with the experimental data reported in the literature, which are used to calculate the interface thermal resistance between Bi 0.5Sb 1.5Te 3 and VO 2. Furthermore, the ratio keff/ Tσeff is found to be higher than the Lorenz number for pure metals. Above the transition temperature of VO 2 (342.5 K), this ratio increases with temperature and concentration, allowing to evaluate the role of electrons as energy carriers in these systems.