BA (boiler ash) (empty fruit bunch ash) was used as a source of pseudo-homogeneous base catalyst for transesterification of palm olein. BA successfully transesterified palm olein at mild reaction conditions (3 wt.% dried BA, 15:1 methanol:oil molar ratio, reaction temperature of 60 degrees C and reaction time of 30 min) to produce 90% methyl esters. Although BA works very well as a catalyst for transesterification, it is not reusable as the active species in the catalyst tend to leach out of the system during reaction. BA was prepared for transesterification by drying in oven at 105 +/- 2 degrees C to constant weight. (C) 2011 Elsevier Ltd. All rights reserved.