Neutron scattering experiments on a proton exchange membrane fuel cell were performed to assess the ability to quantify water in the membrane and electrode/gas diffusion layers. Previous studies have shown that liquid water is easily resolved within flow channels, making neutron imaging a valuable tool in the design and analysis for water management in fuel cells. This study demonstrates the resolution of water content changes within the membrane electrode assembly and membrane alone. These preliminary results extend the use of neutron imaging as a more complete water dynamics measurement tool. including membrane hydration. (c) 2006 Elsevier B.V. All rights reserved.