A new composite hollow fiber ultrafiltration (UF) membrane was prepared with the interfacial polymerization method. A dense layer of polyvinyl alcohol (PVA) was coated on the surface and embedded into the pores of the support polysulfone (PSf) membrane through a dead-end filtration process and cross-linked reaction with diisocyanate (TDI) at room temperature. The surface morphology and functional groups of the composite membrane were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), and Fourier transformation infrared spectrometer (FTIR). Anti-fouling experiments were conducted to study the hydrophilicity and anti-fouling properties of the support and composite membranes. The performances of the composite membrane were significantly influenced by preparation conditions. The composite membrane that performed most efficiently was prepared at an optimal condition: 30 min of dead-end filtration, 0.25 wt% of PVA, 0.50 vol% of TDI, and 60 sec of interfacial reaction. Laboratory scale tests demonstrated that the new composite PVA/PSf membrane has a higher anti-fouling capability and higher flux for oily wastewater treatment. The hydrophilic groups (?OH) enriched in the PVA molecules on the composite surface could play an important role for the improvement of the anti-fouling property and the enhancement of flux recovery rate of the composite membrane. POLYM. ENG. SCI., 2012. (c) 2011 Society of Plastics Engineers