Highly efficient organic bistable light-emitting diodes (OBLEDs) were developed using the tandem structure of organic light-emitting diodes and organic bistable memory. A high external quantum efficiency (> 19.0%) was obtained in the OBLED by combining a green phosphorescent organic light-emitting diode and polymer resistive memory. High quantum efficiency was observed in the OBLED at both the off and on states. The high quantum efficiency was maintained up to high luminance with little efficiency roll-off. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3582803] All rights reserved.