In this work, castor oil was blended with palm and jatropha oils to improve the yield of solvent-free enzymatic methanolysis reaction. Transesterification reactions were carried out with stoichiometric ratio of methanol to oil and using lipozyme TL IM as catalyst at 45 degrees C and 200 rpm for 24 h. By adding only 10% castor oil to the reaction medium a surge in the yield of methanolysis of jatropha oil was observed (i.e. from 21.9% to 65.5%). Increasing the amount of castor oil to 20% raised the yield of methanolysis of jatropha oil to 78.3%. Blending 50% castor oil with palm oil increased the yield of enzymatic methanolysis from 11.9% to 76.2%. Mixing castor oil with jatropha and palm oils improved the yield of solvent free single-step methanolysis reaction to the higher amounts than the maximum theoretical yield of lipozyme TL IM (i.e. 67%). (C) 2012 Elsevier Ltd. All rights reserved.