Nanostructured components are introduced in membrane electrodes assembly (MEA) in proton exchange membrane fuel cell as a solution to improve the performance. Single-walled carbon nanotubes and multiwalled carbon nanotubes supported platinum are used to fabricate the gas diffusion layer (GDL) and the catalyst layers in the MEAs, respectively. The physicochemical and electrochemical characterizations of these nanotube-based components demonstrate excellent GDL surface morphology and uniform distribution of the platinum catalyst over the carbon nanotube support. The fuel cell testing using these nanostructured components exhibits promising fuel cell performance using hydrogen- air and hydrogen-oxygen at ambient pressure. (c) 2006 The Electrochemical Society.