Chitosan membranes with high porosity and good mechanical properties were prepared by selective dissolution of the blend membranes of chitosan (CS) and polyethylene glycol (PEG). The morphology of the obtained porous membranes was characterized by scanning electron microscopy. The pore size changed from 500 nm to several micrometers, depending on the molecular weight of the PEG used. The water permeability of the porous membrane depends on both the pore size and the porosity, except in the case of PEG2000, in which a higher molecular weight of PEG was used, producing greater water permeability. The tensile strength of the porous membranes obtained by this method was higher in both the wet and the dry state than that of the porous chitosan membranes prepared by using silica particles as porogen. (C) 2004 Wiley Periodicals, Inc.