The magnetic CsH2PW12O40/Fe-SiO2 nanocatalysts were prepared via combination of sol-gel and impregnation methods. The effects of different H3PW12O40/(Fe-SiO2) weight percentage, loading of Cs as a promotor and calcination conditions on the catalytic performance has been studied. It was found that the catalyst with H3PW12O40/Fe-SiO2 = 4 wt.% and Cs = 2 wt.% is an optimal catalyst for biodiesel production. The activity of optimal catalyst was studied in different operational conditions. The best operational conditions were CH3OH/oil = 12/1 at 60 degrees C with mechanical stirring rate of 500 rpm and the biodiesel yield reaches to 81% in 4 h. Characterization of catalysts was carried out by using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), N-2 adsorption-desorption measurements methods, Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). (C) 2014 Elsevier Ltd. All rights reserved.