The successful use of radiological equipment in Radiology and the undoubtful help in clinical diagnosis and patient treatment led to the increasing use of this type of equipment. In the old days, the X-ray systems were only found in the Radiological departments of a hospital. In recent years, these machines are used by orthopedic surgeons, angiosurgeons, gastroenterologists in the surgery room, or by interventional radiologists and cardiologists in specialized departments. They are even moving between departments (mobile X-ray systems) for performing urgent radiographs in very ill patients. Apart radiological departments, the personnel is not trained or even informed about the ionizing radiation. The main purpose of this review paper was to : (1) analyze in detail ionizing radiation, (2) to determine the dangers during its use, (3) to note down the main radiation protection rules and (4) finally to provide practical tools for best radiation protection in such hospital departments.