The invention relates to a medical diagnostic system having two C-arms which are adjustable with the aid of two drive means and serve as retaining devices for one medical measuring system in each case. At least one evaluation unit and at least one display element are provided for each medical measuring system. The first measuring system is an X-ray measuring system comprising an X-ray emitter and an X-ray detector and has a high spatial resolution. The second measuring system is a nuclear medicine measuring system for visualizing tissue functions. Accurate and rapid medical diagnoses and interventions are possible based on image information generated by both measuring systems.