The purpose of the present invention is to provide a projection image display device in which all of the multiple light sources to be used are positioned optimally, regardless of the mode of installation of the device. This projection image display device has two illumination optical systems (1, 2) that are each provided with a light source (111, 211), a color separator for separating into three colors of light, a liquid crystal panel (150, 250) for forming an optical image, and a color synthesis prism (160, 260) for color-synthesizing. A polarization beam splitter (3) for synthesis synthesizes an optical image formed by the illumination optical system (1, 2), and projects the same from a projection lens (4). The optical axis (101, 201) of each light source (111, 211) is positioned within the same plane as the optical axis (401) of the projection lens (4), and so as to orthogonally intersect the optical axis (401) of the projection lens.