Sulphated Fe2O3-TiO2 has been synthesized from ilmenite ore and calcined over 300-900 °C. The catalyst samples have been examined for acidity by adsorption of pyridine. The spectral studies reveal the presence of sulphate groups and both Brønsted and Lewis acid sites. The transesterification of soybean oil with methanol is studied over unsulphated and sulphated Fe2O3-TiO2 catalysts with varying sulphate contents and the results are evaluated on the basis of acidity. The catalyst samples calcined below 500 °C show higher conversion of vegetable oil with significant yield of biodiesel which could be due to the greater affinity of hydroxyl groups of methanol on Fe2O3-TiO2. The sulphated Fe2O3-TiO2 samples calcined above 500 °C show lower conversion of biodiesel and this is proposed to be due to the removal of sulphate groups during calcination. © 2014, Scientific Publishers. All rights reserved.