An organic light emitting display including a scan signal line forwarding a scan signal, a data line sending a data signal and a pixel coupled to the scan signal line and the data line, the organic light emitting diode display, wherein the pixel includes a first switching transistor transmitting a data signal from the data line in response to the scan signal of the scan signal line, a driving transistor, coupled to the first switching transistor, controlling driving current from a first power source line, a storage capacitor coupled between the driving transistor and the first power source line, an organic light emitting diode, coupled between the driving transistor and a second power source line, displaying an image with the driving current controlled by the driving transistor, an initial switching transistor, coupled between the storage capacitor and an initial power source line, initializing the storage capacitor, and a switching transistor for applying a reverse bias, coupled between the second power source line and the initial power source line, applying a reverse bias voltage to the organic light emitting diode.