The present invention relates to a lighting device for vehicles including at least one diffuser body suitable for receiving light emitted by a light source so as to diffuse the light externally to the body. The diffuser body includes a solid matrix of transparent polymer material which incorporates a plurality of bubbles or cavities, wherein the solid matrix performs the transmission of light within the body by subsequent reflections and wherein the bubbles perform the diffusion of light and the extraction thereof outside the body by subsequent refractions.