Perovskite La0.6Sr0.4Co0.2Fe0.8O3 hollow fibre membranes were prepared by a combined phase-inversion and sintering technique. The prepared membrane was further modified by a facile acid etching method at room temperature to form a novel dual structure consisting of a central dense layer sandwiched by two porous layers on both surface sides. Oxygen permeation measurements revealed that the modified membranes possess much higher oxygen fluxes than the original hollow fibres due to the newly formed structure. (C) 2008 Elsevier B.V. All rights reserved.