Embodiments of this document provide a stereoscopic image display device and a driving method capable of preventing the reduction in resolution when 3D images are displayed on a stereoscopic image display device including a patterned retarder. According to an exemplary embodiment, in odd numbered display lines of a display panel, left eye image data input during an N-th (where N is a positive integer) frame period is displayed during the N-th frame period, and left eye compensation image data generated based on the data input during the N-th frame period is displayed during a (N+1)-th frame period, and in even numbered display lines of the display panel, right eye compensation image data generated based on data input during a (N−1)-th frame period is displayed during the N-th frame period, and right eye image data input during the (N+1)-th frame period is displayed during the (N+1)-th frame period.