Sensitized mesoporous ZnO films were prepared by a three-step procedure comprising the electrodeposition of ZnO in the presence of Eosin Y serving as a structure directing agent, its desorption and the adsorption of the sensitizer cis-bis(isothiocyanato)bis(2,2(')-bipyridyl-4,4(')-dicarboxylato)-ruthen ium(II) often referred to as N3 or N535. The obtained optimized electrodes exhibit high external quantum yields (IPCE) of up to 55% in the absorption maximum of N3, being clearly superior to electrodes obtained earlier by a one-step procedure involving the addition of the N3 dye to the deposition bath. Compared to other reported N3/ZnO electrodes, the newly developed ones are to be preferred because of a high IPCE for substantially thinner films prepared in a low-temperature process. The changes in the film surface area following individual preparation steps were monitored by krypton sorption measurements. The N3 adsorption conditions were optimized in order to maximize the dye load but to maintain an open pore structure and to avoid dye agglomeration. Time-resolved photocurrent measurements in the millisecond regime were used to analyze the electrode kinetics and detect recombination reactions.