Ethyl cinnamate, an ester known as flavor and fragrance compound, has been synthesized using two immobilized bioreactor systems, batch and fluidized bed bioreactors. The enzyme used for this synthesis is a commercial lipase B preparation, Novozyme 435. Initial kinetic studies were conducted in both employed bioreactor configurations, and kinetic constants were obtained. Several models were tried for fitting of experimental data, but the best fit, for both bioreactors, was obtained when the ping-pong bi-bi mechanism was used. Interestingly enough, ethanol inhibition occurred in batch bioreactor, but it did not exist in the fluidized bed bioreactor. Solid-liquid mass transfer coefficients were calculated for both bioreactors to determine whether mass transfer limitations existed in either of these systems. The calculation of Damkohler numbers and Thiele modulus confirmed that mass transfer limitations had no effect on the overall reaction in both bioreactors.