Ultrafiltration membranes composed of polyethersulfone (PES) and aminated PES (PES-NH2) were fabricated using a non-solvent-induced phase separation process, and then zinc oxide (ZnO) nanoparticles were assembled onto the membrane surface. To assemble ZnO nanoparticles onto the PES/PES-NH2 membrane surface, thionyl chloride-terminated ZnO nanoparticles were reacted with the amine groups in PES-NH2. The formation of PES-NH2 and PES/PES-NH2 membranes assembled with ZnO nanoparticles was confirmed using FT-IR, XPS, FE-SEM, and EDS analyses. The hydrophilicity and water flux of the membranes increased with increasing PES-NH2 content. No antibacterial activity was observed for PES/PES-NH2 membranes, while PES/PES-NH2 membranes assembled with at least 0.8 wt% ZnO nanoparticles displayed antibacterial activity (=6.1). Membranes having antibacterial activity, high water flux, and improved fouling resistance without a loss in solute rejection were fabricated by assembling ZnO nanoparticles onto the PES/PES-NH2 membrane surface. (C) 2016 Elsevier Ltd. All rights reserved.