BACKGROUND The use of ionizing radiation is regulated by legislative bodies to limit both individuals' and the population's exposure to radiation. Germany has implemented the European 97/43/EURATOM directive in national law by updating the existing radiation protection regulations. The German Commission on Radiological Protection regularly publishes statements and recommendations on radiation protection in medicine and diagnostic radiology, such as the introduction of diagnostic reference levels and referral guidelines for radiological and nuclear medicine imaging. METHODS Review of selected literature, national and international recommendations and legal texts. RESULTS From a radiological protection perspective, clear justification for radiological examinations and techniques aimed at minimizing radiation dose while providing the required diagnostic information, are essential. CONCLUSIONS Referring doctors should be sure to use existing guidelines for medical imaging, and liaise with radiologists and nuclear medicine specialists, with whom they share the responsibility for choosing appropriate imaging modalities.