An object of the invention is to provide a stereoscopic image display device, which does not generate a non-display region when an observer observes each parallax image despite being a stereoscopic image display device for displaying a multi-visual point image, and has little reduction of the image quality.The stereoscopic image display device of the present invention has an image display means for displaying the synthesized image obtained by synthesizing a plurality of parallax images, an aperture portion, a light-shielding portion, and horizontal directional control means for giving a directivity toward each of the desired directions to the image information light including the information on the parallax image radiated from the image display means, wherein longitudinal enlarging means for enlarging longitudinally only the light beam having passed the aperture of the horizontal directional control means in directions is disposed in front of the horizontal directional control means.