Esterification of free fatty acids in Pongamia pinnata oil has been carried out using two different zeolites. Classical optimization of reaction parameters were carried out with H-ZSM 5 and H-Y zeolites. Based on the experimental results, a methanol to oil ratio of 9:1, with 1% by weight catalyst, a reaction time of 1 h and temperature 60 degrees C were selected as the optimum for the esterification reaction. Kinetic studies were undertaken and the reaction was found to fit a pseudo first order kinetics.