A projection display device that promotes size reduction thereof, and that allows an optical system including optical modulation devices to be equitably and efficiently cooled. The projection display device includes a head body having an optical modulation device, a color synthesizing optical system, and a projection lens mounted thereon, a fan disposed in the head body, and a fan frame mounted on a prism bearing face at a plurality of points so as to hold the fan. The fan frame has a face that faces the prism bearing face and is shaped substantially like a quadrangle in outline, and one of the two diagonal lines of the quadrangle extends along the plane orthogonal to the prism bearing face. This makes it possible to mount the fan frame close to the projection lens side, and to thereby promote size reduction.