Calcined bovine bone waste was employed to catalyze the transesterification reaction between soybean oil and methanol. The influence of various conditions on the efficiency of the transesterification was studied i.e. type of reactor, temperature, catalyst loading and methanol/oil ratio. The optimum yield of methyl ester (97%) was obtained by performing the closed-system transesterification at 65 degrees C for 3 h with catalyst loading of 8% wt and 6:1 methanol to oil ratio, using bone calcined at 750 degrees C. Calcination of the commercial bovine bone at 650 degrees C and above results in conversion of the calcium carbonate component to calcium oxide, with the major component being crystalline hydroxyapetite. Calcium oxide is believed to be responsible for the catalytic activity of the material. The reusability, low cost and low catalyst loading required (4% wt) may make bovine bone an attractive alternative to existing transesterification catalyst systems. (C) 2013 Elsevier Ltd. All rights reserved.