Modification of wool fabrics With an enzyme in a reverse micellar system has been investigated using polyoxyethylene sorbitan trioleate as a surfactant. The Protease, Bioprase 30L, used in this study was satisfactorily solubilized in the reverse micellar system and maintained its activity even in an organic media. Modification of wool fabrics with Bioprase 30L was evaluated by the fabric's weight loss, measurement of tear strength, scanning electron microscopy, and measurement of shrinkage. Effective modification of wool fabrics with enzymatic hydrolysis can be attained without causing serious loss of fiber strength. (C) 2004 Society of Chemical Industry.