Racemic mandelic acid was resolved by transesterification with vinyl acetate catalysed by Pseudomonas cepacia lipase. A high enantiomeric excess (>99%) of both unreacted substrate and acylated product was obtained at 25 degrees C using diisopropyl ether as the reaction medium. The Ping-Pong Bi-Bi mechanism and second order kinetics have been used to model the reaction rate. The best estimation has been obtained for the Ping-Pong Bi-Bi model without inhibition. Values of kinetic parameters were estimated.