A patient-positioning device and a medical workstation including the patient-positioning device. The patient-positioning device includes a patient couch and a robot arm which is provided for moving the patient couch and which comprises several links arranged one after another and mounted rotatably with respect to axes. The robot arm includes, as links, a start link, a first link, a second link, a third link, a fourth link, a fifth link and a sixth link. The robot arm comprises a patient couch or a fastening device on which the patient couch is fastened.