A new multiphase enzyme membrane reactor has been developed by immobilizing the lipase from Candida rugosa in a polymeric membrane in presence of a stable and uniform oil-in-water emulsion prepared by membrane emulsification. The reactor had a configuration of a two separate phase membrane reactor constituted by an emulsion + enzyme-loaded membrane and an organic and an aqueous phase recycled along the two separate sides of the membrane. The reactor was tested with different naproxen esters and with triglycerides as reagents and its performance was compared with the traditional two separate phase enzyme membrane reactor where the lipase was immobilized without emulsion. The results showed that the presence of emulsion within the membrane improved the catalytic activity and the enantioselectivity of the immobilized enzyme as well as the transport rate of the hydrophobic reagent through the hydrophilic membrane. The work confirmed that immobilization can either improve enzyme stability than preserve its native selectivity. (C) 2007 Elsevier B.V. All rights reserved.