Perovskite hollow fibre membranes of the chemical composition BaZrxCoyFezO3-delta (BCFZ) have been developed using a phase inversion spinning process followed by sintering. The BCFZ hollow fibre membranes show an O-2 flux of 7.6 ml/n-tin/cm(2) at 900 degrees C which is the highest value so far known. From the Wagner theory it follows that the O-2 transport through thin walled perovskite hollow fibre membranes is controlled by both vacancy diffusion and interface reactions. (c) 2005 Elsevier B.V. All rights reserved.