A light diffusion film in which the angle of aperture of diffused light has been expanded effectively by forming, within the film, a predetermined columnar structure composed of pillar-shaped objects having a bent part and a region having a relatively low refractive index, and a method for manufacturing the light diffusion film are provided. Disclosed is a light diffusion film having a columnar structure in which plural pillar-shaped objects having a relatively high refractive index are arranged to stand close together in the film thickness direction in a region having a relatively low refractive index, and the plural pillar-shaped objects having a relatively high refractive index have a bent part in the middle of the pillar-shaped objects.