An organic light emitting diode (OLED) display device is disclosed. In one aspect, the OLED display device includes a driver that receives image data and generates a data signal and a scan signal corresponding to the image data, and an organic light emitting display panel that receives the data signal and the scan signal and displays an image corresponding to the image data, wherein the scan signal includes a scan-on period and a scan-off period, and when gray scales of the image data increase, the length of the scan-on period increases.