For fabrication of plastic dye-sensitized solar cells, we propose a dissolution and precipitation method to form nanostructured ZnO films on plastic substrates. Layered hydroxide zinc acetate (LHZA) films on plastic substrates were immersed in acetonitrile at 60 °C. They were converted into ZnO films through the dissolution of LHZA and the precipitation of ZnO in acetonitrile. The resultant films contained a large amount of zinc acetate compound impurities, which were attempted to be removed from the ZnO films by dissolving in water. We achieved the energy conversion efficiency of 2.3% for the N719/ZnO electrode on an ITO-PEN substrate.