A laser projection device is provided and includes a laser light source, a diffusion plate, and a housing. The diffusion plate has an incidence surface and an emission surface and emitted light from the laser light source is incident thereon. A plurality of linear grooves are arranged in at least one of the incidence surface and the emission surface. The housing has an opening through which lightdiffused by the grooves is emitted in an emitting direction of the laser light source.