Disclosed is a stereoscopic image display device which separates views from each other to reduce crosstalk and minimizes reduction in brightness due to decrease of an opening area of sub-pixels. The stereoscopic image display device includes a display panel including first and second sub-pixels arranged in parallel in the horizontal direction in each of regions formed by intersecting a plurality of gate lines and a plurality of data lines, openings for opening a part of each of the first and second sub-pixels in a light-shielding pattern configured to shield regions of the first and second sub-pixels other than the openings, and a parallax unit located on the display panel and including a plurality of lenses.