An organic light emitting display device includes a pixel, a data line, a first scan line, a second scan line, and a scan driver. The pixel includes a first transistor, a second transistor, and a third transistor. A source of the first transistor is electrically connected to a drain of the third transistor. A source of the second transistor is configured to receive an initialization voltage. The data line is electrically connected to a source of the third transistor and may transmit a data voltage higher than the initialization voltage. The first scan line is electrically connected to a gate of the third transistor. The second scan line is electrically connected to a gate of the second transistor. The scan driver may provide an initializing scan signal to the second scan line at least two horizontal periods before providing an initial scan signal to the first scan line.