Biodiesel is a biofuel expected to become a substitute for petroleum diesel. One of the most promising technologies for production of biodiesel is enzymatic catalysis. However, low catalytic performance of most of the enzymes employed makes such processes expensive and time-consuming. This work describes a kinetic study of the enzymatic production of biodiesel at different temperatures using either methanolysis or ethanolysis, using immobilized lipase from Candida antarctica (Novozym 435) as catalyst. Reactions kinetics were followed by GC, and data were used to perform thermodynamic analysis of the transition state using Arrhenius equation. We found that methanolysis is faster than ethanolysis at temperatures above 13 degrees C. Thermodynamic analysis of the kinetics of reactions showed that methanol is favored as acyl acceptor due to the positive activation entropy change of reaction. These data may be useful in the development of new enzymes and new processes for enzymatic production of biocliesel. (c) 2011 Elsevier B.V. All rights reserved.