An organic light-emitting display device which divides each frame into a plurality of sub-frames and represents gray levels based on the sum of the lengths of one or more sub-frames during which light is emitted, the organic light-emitting display device comprising a display unit including a plurality of pixels arranged in a matrix, a scan driver configured to provide a scan signal to the display unit during each sub-frame period and a precharge voltage unit configured to provide a precharge voltage to the pixels, wherein the pixels are divided into a first pixel column block including a pixel receiving the scan signal before the other pixels and a second pixel column block next to the first pixel column block in a direction of the application of the scan signal and the precharge voltage is selectively provided to pixels included in the first pixel column block.