Nanostructured platinum prepared by the chemical reduction of hexachloroplatinic acid dissolved in aqueous domains of the liquid crystalline phases of oligoethylene oxide surfactants. was examined as an electrocatalyst for the electrooxidation of formic acid. The electrocatalytic properties of the catalyst combining highly specific surface areas and a periodic mesoporous nanostructure were accessed in sulfuric acid solution containing 0.5 mol dm(-3) formic acid using cyclic voltammetry (CV) and chronoamperometry. The electrocatalytic activity of the material at 60 degreesC. is characterised by a mass activity of 8.6 A g(-1) and a specific surface area activity of 26 muA cm(-2) at 0.376 V (vs. RHE). The resistance to CO poisoning was found to depend upon electrode potential. At hydrogen adsorption potentials. the material is easily poisoned, while the material shows high resistance to CO poisoning at potentials positive of the hydrogen region. These facts suggest that the decomposition of HCOOH on the mesoporous platinum is likely to proceed through a dual-path mechanism and the high surface area material is a potential electocatalyst towards the electrooxidation of small organic molecules.