A scan driving unit and OLED display device including the unit are disclosed. In one aspect, the unit includes a first pre-decoder block that receives upper scan-line selection signals for selecting one of upper scan-lines that are arranged in an upper display region of a display panel, and outputs first logic signals based on the upper scan-line selection signals. It also includes a second pre-decoder block that receives lower scan-line selection signals for selecting one of lower scan-lines that are arranged in a lower display region of the display panel, and outputs second logic signals based on the lower scan-line selection signals. It further includes a first final-decoder block coupled between the upper display region and the first pre-decoder block that selects one of the upper scan-lines based on the first logic signals, and a second final-decoder block coupled between the lower display region and the second pre-decoder block that selects one of the lower scan-lines based on the second logic signals.