A new type of forward osmosis (FO) hollow fiber membranes with an antifouling nanofiltration (NF)-like selective layer has been developed in this work. The fabrication involves a step of porous poly(amide-imide) (PAI) ultrafiltration (UF) hollow fiber spinning via phase inversion, followed by simple polyelectrolyte post-treatments using positively charged polyethyleneimine (PEI) for cross-linking and negatively charged polystyrene sulfonate sodium salt (PSS) for deposition. The membranes are subsequently characterized by a series of standard protocols and evaluated in FO process. The PAI FO membranes possess a pure water permeability of 3.7-4.3 L m(-2) h(-1) bar(-1) and Na2SO4 rejections up to 85% at 1 bar. In the FO process, the membranes can achieve water flux of 17 and 12 L m(-2) h(-1) for active layer facing draw solution (AL-facing-DS) and active layer facing feed water (AL-facing-FW) configurations, respectively, using a 2000 ppm Na2SO4 aqueous solution as the feed and 0.5 M Na2SO4 as the draw solution. When the feed contained 1000 ppm bovine serum albumin (BSA) and 2000 ppm Na2SO4, a steady water flux of 11 L m(-2) h(-1) can be maintained using 0.5 M Na2SO4 as the draw solution at ambient temperature of 23 degrees C. The approach of making FO membranes developed in the present study offers the advantages of simple fabrication process, tailorable selective layer and promising membrane performance for protein-contained wastewater treatment by FO process. (C) 2011 Elsevier B.V. All rights reserved.