A lighting and signaling device for automotive vehicles, comprising a container body delimiting a containment housing closed by a lenticular body, which accommodates at least one first light source and is closed by a lenticular body, a first light guide configured to receive as input at least partially the light beam produced by the first light source, transmits the light beam by total internal reflection along a first prevailing propagation direction and sends it as output from the lenticular body. A fixing and/or screen element, opaque to the light beam is associated with the first light guide at a first interface wall, and is fixed either directly or indirectly onto the container body to mechanically block the first light guide onto the container body. The first light guide is mechanically fixed to the fixing and/or screen element by at least one first welding portion which projects from the first interface wall.