In this work, vanadium pentoxide supported on rice husk ash containing 5,10 and 15 mass% of V2O5 were prepared by the urea combustion method. These samples were characterized by FTIR (Fourier - transform infrared spectroscopy) and XRD (X-ray diffraction) and applied in the reactions of transesterification with ethanol by using different triglycerides sources, namely as soybean oil, frying oil and chicken fat. The XRD data of the V2O5/RHA showed reflections associated with the silica, sodium silicate and V2O5. The FTIR spectra of the V2O5/RHA samples containing 5 to 15 mass% of V2O5 presented absorptions related to silica, silicates and possible V-O-Si interactions, also been observed in the 15% V2O5/RHA an FTIR band associated to V2O5. The H-1 NMR (proton nuclear magnetic resonance) and GC-FID (gas chromatography with flame ionization detection) analysis of the transesterification reactions presented conversions of triglycerides for biodiesel over 90% in a period of 6 h, demonstrating the potential of V2O5/RHA for the synthesis of ethyl biodiesel. (C) 2015 Elsevier Ltd. All rights reserved.