We present a viable method to enhance the current efficiency of organic light-emitting diodes (OLEDs) byimprinting cylindrical nanopatterns (NPs) onto a glass substrate. Herein, OLEDs equipped with an optimumNP array having a diameter of 300 nm and a periodic distance of 500 nm show a 33.4% improvementin current efficiency compared with a device without NPs. The light extraction efficiency of OLEDs wasenhanced using a nanopatterned glass substrate, without any electrical degradation owing to the formationof NPs on opposite sides of the organic layers. In addition, top-emitting OLEDs can be fabricated easilyby patterning the encapsulation glass.