The esterification of a long-chain fatty acid was conducted using a nylon-immobilized lipase from Candida cylindracea in a nearly anhydrous, nonpolar organic medium, hexane. Butyl laurate was produced from lauric acid and n-butanol at a maximum initial reaction rate of 37 mmol/h . g immobilized enzyme when the substrates were present in equimolar amounts at an initial concentration of 0.5 mol/L. Lower rates were obtained using nonstoichiometric amounts of the substrates. The rate of reaction increased with temperature, reaching a maximum between 35 and 45 degrees C and decreasing sharply at higher temperatures.