A newly developed method is presented which allows the characterization of the electrocatalytic properties of highly dispersed electrocatalysts in a true rotating disk electrode (RDE) configuration by attaching the catalyst powder on a glassy carbon electrode via a thin Nafion film. Complete utilization and high reproducibility of both the electrode preparation and the catalyst loading could be shown via voltammetry and CO stripping voltammetry. Furthermore, RDE measurements on the electro-oxidation of hydrogen on Pt/Vulcan showed that the effect of diffusion through the Nafion film can be avoided by proper electrode preparation. Therefore, the electrode kinetics for fuel cell relevant reactions under continuous now conditions can be measured directly without mathematical modeling.