An organic light emitting display device operating in a concurrent (e.g., simultaneous) emission method, which includes a first power driver configured to apply first power, which changes between a first low level and a first high level, to pixels of the display unit, and a second power driver configured to apply second power, which changes between a second low level and a second high level, to the pixels, wherein each of the pixels includes an organic light emitting diode, a driving transistor configured to control an amount of current supplied to the organic light emitting diode, and an initializing transistor coupled to an anode electrode of the organic light emitting diode and configured to be turned on during a reset period in one frame to supply a reset voltage, which is lower than the first high level of the first power, to the anode electrode of the organic light emitting diode.