A rotating data transmission device for computer tomographs, for transmission from a rotating part to a stationary part that is rotatably supported relative to the rotating part, comprises at least one dielectric waveguide assigned to the rotating part, at least one first line coupler for coupling electrical signals into the at least one dielectric waveguide, and at least one coupler assigned to the stationary part for tapping electrical signals from the at least one dielectric waveguide. The dielectric waveguide is divided into at least two segments of approximately the same length, signals are coupled into the segments of the dielectric waveguides through a first line coupler to propagate in opposite directions, and ends of the segments distant from the line coupler are provided with terminations.