Abstract Lipase ( Candida rugosa) was entrap-immobilized on cellulose acetate-titanium iso-propoxide gel fiber by the sol-gel method. The immobilized lipase was used for the direct synthesis of ( S)-ibuprofen ester from racemic ibuprofen using propyl alcohol as an acyl acceptor in isooctane. The activity of the immobilized lipase was decreased to about 10–20% that of native lipase. However, the reaction was more enantioselective compared to that with native lipase. The stability for repeated use was improved by immobilization.