A stereoscopic image display device includes a display panel including a plurality of left eye pixels and a plurality of right eye pixels, a memory including a left eye image section for storing data corresponding to the left eye pixels and a right eye image section for storing data corresponding to the right eye pixels, a geometric engine for converting an input 3D image data into left eye 3D image data corresponding to the left eye pixels or right eye 3D image data corresponding to the right eye pixels, and a rendering engine for calculating a coordinate value and a color information value to be stored in the left eye section or the right eye section by using coordinate and color information of the left eye 3D image data or the right eye 3D image data, and for storing the color information value in the memory based on the coordinate value.