A plasma display device and a method of driving the same. Embodiments of the present invention provide a plasma display device and a method of driving the same with a reduced number of power supplies and improved performance. During a reset period, a voltage that gradually increases to two times as much as the sustain voltage is applied to a scan electrode, the sustain electrode is electrically floated during a period of the reset period when the voltage of the scan electrode is gradually decreased. A reference voltage is applied to a plurality of scan electrodes to which a scan voltage is not applied during an address period, as a non-scan voltage.