A stereoscopic image display includes a display panel including pixels and a patterned retarder. Each pixel includes a main display unit including a first pixel electrode connected to a data line through a first thin film transistor (TFT) and a first common electrode connected to an upper common line, an auxiliary display unit including a second pixel electrode, which is connected to the data line through a second TFT and is connected to the upper common line through a discharge control TFT, and a second common electrode connected to the upper common line, and a line unit between the main display unit and the auxiliary display unit. The line unit includes a gate line, through which a scan pulse is applied to the first and second TFTs, and a discharge control line, through which a discharge control voltage is applied to the discharge control TFT.