The projection display system has a light source unit where a first light source and a second light source respectively emitting a first and second wavelength or wavelength range of light are juxtapositionally arranged; a third light source emitting a third wavelength or wavelength range of light; an optical combiner device for combining the three wavelengths or wavelength ranges of light from the light sources; an optical device for averaging distributions of the wavelengths or wavelength ranges of light; an image display device for receiving the light transmitted through the optical device and forming image light responsive to a video signal; and a projector lens for projecting the image light onto a screen. At least two of the optical axes of the first, second, and third wavelengths or wavelength ranges of light which are incident on the optical device are not coincident with each other.