A novel electrodeposition technique for preparing the catalyst layer in polymer electrolyte membrane fuel cells has been designed, which may enable an increase in the level of platinum utilisation currently achieved in these systems. This method consists of a two-step procedure involving the impregnation of platinum ions into a preformed catalyst layer (via an ion-exchange into the Nafion polymer electrolyte), followed by a potentiostatic reduction. The concentration of Nafion within the catalyst layer was found to have a significant bearing on the size of the platinum deposits. The preparation of catalyst layers containing a desired platinum loading should also be possible using this method. Surface areas of the platinum deposits were determined using cyclic voltammetry. The prepared catalyst was compared with a conventional electrode made from E-TEK Pt/C. Scanning electron microscopy was used to investigate the dispersion of the platinum particles. Platinum loadings were determined quantitatively by atomic absorption spectroscopy.