An organic electroluminescent display device includes a scan line, a data line, a voltage supply line, a switching transistor connected to the scan and data lines, a driving transistor connected to the switching transistor and the voltage supply line, a storage capacitor connected between the switching transistor and the voltage supply line, and an organic light-emitting diode connected to the driving transistor and ground. A black display voltage applied to the data line is supplied to the driving transistor when a first gate ON signal is applied to the scan line. A video data voltage applied to the data line is supplied to the driving transistor when a second gate ON signal is applied to the scan line. The voltages are applied at least once each frame.