Abstract: A light diffusion sheet usable, for example, in backlight units, includes a transparent substrate layer, and a light diffusion layer overlaid on a front face of the substrate layer. The light diffusion layer includes resin beads and a resin binder, the resin beads being provided as monodisperse beads having a mean particle size of 1.5 ?m or greater and 5 ?m or less. A weight ratio of the monodisperse beads to the binder is 2.5 or greater and 3 or less, and an amount of the overlaid light diffusion layer is 3 g/m2 or greater and 10 g/m2 or less. An acrylic resin may be used as the substrate polymer of the monodisperse beads and binder. A coefficient of variation of particle size distribution of the monodisperse beads is preferably equal to or less than 0.2. Advantageously, a gravure coating method is employed for forming the light diffusion layer.