Babassu biodiesel was obtained by ethanolysis using Burkholderia cepacia lipase immobilized on SiO 2 -PVA as catalyst in microwave reactor. The effect of temperature and the ethanol-to-oil molar ratio on the biodiesel yield was studied using rotational central composite design (CCD). Under optimal conditions, full conversion was attained at a reaction time of 10h. The purified product contained no glycerol-bound compounds, as verified by 1 H NMR. In addition, other properties, such as specific gravity (870kgm −3 ) and viscosity (4.2mm 2 s −1 ), are in accordance with standard fuel specifications.