An investigation of membrane materials for the cross-flow microfiltration of water-in-oil emulsions is reported. The membrane used were, PTFE, PVDF and nitrocellulose. The emulsion considered was water with kerosene using Span 80 as surfactant. The effects of operating conditions: cross-flow velocity, trans-membrane pressure, temperature and emulsion concentration is described and analysed in terms of a fouling index for filtration. An increase in trans-membrane pressure, temperature and flow rate of emulsion all result in an increase in membrane flux. Membrane flux falls initially with time under most conditions of operation, except at a temperature of 50 degrees C, where flux are stable. The use of corrugated membranes is shown to produce a large increase in flux rate in comparison to the use of flat membranes under the same conditions and cross-flow velocities. (C) 2007 Elsevier B.V. All rights reserved.