A large variety of microporous polymer films can be prepared by the breath figure technique. Here, we report on its use for the formation of microporous zinc oxide films. Zinc acetylacetonate, a zinc oxide precursor, is either dissolved in a polymer solution that is cast at high humidity to form microporous films or is vacuum evaporated onto a preformed microporous polymer film. Annealing leads to the pyrolysis or the organic material and the formation of zinc oxide films, which show increased photoeatalytic activity as compared to unstructured films.