Radiographic diagnostic device has a projection unit that is formed as a computer tomography system with a radiation emitter and a line detector, which are constructed such that they can be rotated around a projection area opposite one another. A support apparatus with a support plate for an examination subject is provided. The radiographic diagnostic device has an additional radiation receiver allocated to it so that the additional radiation receiver can be moved from a standby position into a pick-up position for receiving a radiation beam that emanates from the radiation emitter of the computed tomography system. Both computed tomography projections and conventional X-ray projections can be obtained with the radiographic diagnostic device when the additional radiation receiver is realized as a radiographic film, a solid-state detector, or a storage foil.