Illumination device for vehicles with a flat light-conducting element , - which has opposing flat sides at which light coupled in is totally reflected, - which has a first narrow side in a light coupling-in area for coupling in the light, - which has a second narrow side in a light coupling-out area for coupling out the light in the main radiation direction (H) of the illumination device, - which has a connecting side joining the first narrow side and the second narrow side , - that an elongated optical waveguide is provided, which follows the contour of the first narrow side of the flat light-conducting element and has a first end face arranged at the end and a second end face between which an outer surface of the elongated optical waveguide extends, which has coupling-out elements for deflecting the light coupled into the elongated optical waveguide , so that the light is coupled out of the elongated optical waveguide in the direction of the first narrow side of the flat light-conducting element by a longitudinal section of the outer surface towards the first narrow side of the flat light-conducting element , - that the flat light-conducting element is not designed to be level, - and that the flat light-conducting element rises from a base plane (B) spanned by an extension plane (E 1 ) of the second narrow side and a main radiation direction (H) in the direction of a rear corner region of the light guiding element , said corner region being arranged on a side facing a body end edge , and - that the first narrow side is twisted by a twist angle (φ 1 ) in the direction of the corner region relative to an extension line (E 3 ) of the first narrow side and/or the connecting side is twisted by a twist angle (φ 2 ) in the direction of the corner region relative to an extension line (E 2 ) or the connecting side . - which has opposing flat sides at which light coupled in is totally reflected, - which has a first narrow side in a light coupling-in area for coupling in the light, - which has a second narrow side in a light coupling-out area for coupling out the light in the main radiation direction (H) of the illumination device, - which has a connecting side joining the first narrow side and the second narrow side , - that an elongated optical waveguide is provided, which follows the contour of the first narrow side of the flat light-conducting element and has a first end face arranged at the end and a second end face between which an outer surface of the elongated optical waveguide extends, which has coupling-out elements for deflecting the light coupled into the elongated optical waveguide , so that the light is coupled out of the elongated optical waveguide in the direction of the first narrow side of the flat light-conducting element by a longitudinal section of the outer surface towards the first narrow side of the flat light-conducting element , - that the flat light-conducting element is not designed to be level, - and that the flat light-conducting element rises from a base plane (B) spanned by an extension plane (E 1 ) of the second narrow side and a main radiation direction (H) in the direction of a rear corner region of the light guiding element , said corner region being arranged on a side facing a body end edge , and - that the first narrow side is twisted by a twist angle (φ 1 ) in the direction of the corner region relative to an extension line (E 3 ) of the first narrow side and/or the connecting side is twisted by a twist angle (φ 2 ) in the direction of the corner region relative to an extension line (E 2 ) or the connecting side . <EOS>