A gas humidification sub-system that does not add to the parasitic power loss is advantageous for water management in PEMFC. A membrane humidifier was fabricated with porous membrane and the performance of the single cell using this humidifier has been evaluated. The study shows that the performance of the humidifier is comparable to that of the bubble humidifier. It was further found that the humidifier is suitable for both water and exhaust cathode air as the humidifying medium. Copyright (C) 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.