To provide a light diffusing pressure-sensitive adhesive sheet having stable light diffusing performance, without local irregularities, no decrease in the light diffusion performance even in a high temperature and high humidity environment, and has superior durability without blistering, peeling, foaming or the like.

The light diffusing pressure-sensitive adhesive sheet comprises a substrate and a pressure-sensitive adhesive layer, having light diffusing property, formed on at least one surface of the substrate, wherein the pressure-sensitive adhesive layer contains a pressure-sensitive adhesive having a refractive index of not less than 1.48 and fine particles having a refractive index of not more than 1.46.