PVDF hollow fibre membranes with interconnected bicontinuous structures were produced from PVDF/TEP solutions using a single-step phase inversion method. Hollow fibres with excellent mechanical strength and very dense inner and outer skin layers were obtained using a PVDF/TEP solution. Due to the hydrophobic nature of PVDF and formation of the dense skin layers, the produced membranes were not suitable for water and wastewater applications. In order to improve the water flux, two different molecular weight PEGs were employed to eliminate the dense skin and as pore-forming agent additives. A wide range of ultrafiltration hollow fibre membranes, suitable for water and wastewater treatments and similar to modified industrial PVDF ultrafiltration membranes were produced by using PVDF/TEP/PEG dope solutions with the adjusted spinning parameters. (C) 2012 Elsevier B.V. All rights reserved.