Radiation is the transfer of energy in which energy waves, or particles, travel through a vacuum or matter. The radiation that causes ionization is called ionizing radiation. The use of ionizing radiation in medical diagnostics has found wide application. With the discovery of X-rays, begins the development of radiology, which is considered a branch of medicine that deals with the application of various types of radiation to diagnose and treat various types of diseases. With the development of the science of medicine, both medical technology and X-ray technology are evolving. Today, there are many designs of X-ray devices, which are used in diagnosing disease, and can be used to treat disease. The increasing use of ionizing radiation, if not used properly, increases the possibility of harmful hazards. Medical technicians who are exposed to ionizing radiation on a daily or intermittent basis during their work can reduce the risk of adverse effects of radiation by appropriate occupational safety and health measures that will prevent unnecessary exposure to high doses. This final work will explain the application of ionizing radiation in medicine, how it affects humans, and will describe the radiological equipment whose work is based on ionizing radiation.