An organic light emitting display device includes a scan driver for sequentially supplying a scan signal through scan lines; a data driver for supplying an initial power through data lines during a first period of a time period when the scan signal is supplied through a corresponding scan line of the scan lines, and for supplying data signals to the data lines during a second period of the time period when the scan signal is supplied through the corresponding scan line, the second period following the first period; and pixels at crossing regions of the scan lines and the data lines.