A simple and efficient approach towards the fabrication of a skinned membrane with highly ordered pores in the nanometer range is presented here. We successfully combined the self-assembly of PS-b-FED block copolymer and water induced phase separation for the preparation of isoporous PS-b-FED block copolymer membranes. We produced for the first time asymmetric isoporous PS-b-FED membranes with a 100 nm thin isoporous separating layer using water at morn temperature as coagulant. This was possible by careful selection of the block lengths and the solvent system. FESEM, AFM and TEM measurements were employed to characterize the nanopores of membranes. The pure water fluxes were measured and the flux of membrane was exceptionally high (around 800 Lm(-2) h(-1) bar(-1)). Protein rejection measurements were carried out for this membrane and the membrane had a retention of about 67% of BSA and 99% of gamma-globulin. (C) 2013 Elsevier B.V. All rights reserved.