We have developed a large-area hydrophilic plastic film using a nanostructure. Using a transparent poly(ethylene terephthalate) (PET) film with the pillarlike nanostructure, the super-hydrophilic effect on the plastic surface emerged when the surface was covered with huge amounts of water droplets. The super-hydrophilic effect continued for over 60 days which was longer than that of other hydrophilic materials. In addition, the PET film with the pillarlike nanostrcture was produced by an imprinting process only. Thus, it was confirmed that super-hydrophilic PET film can be prepared by a low-cost process.