Radiation emergency medicine (REM) systems are operated around the world to provide specialized care for injured individuals who require immediate medical attention in accidents. This manuscript describes the current status of REM safety regulation in Korea and summarizes an assessment of the effects of this regulation. Responding to the requests of people for stronger safety regulations related to radiation exposure, a unique REM safety regulation for nuclear licensees, which is enforceable by laws, has been established and implemented. It is not found in other countries. It can provide a good example in practice for sustainable REM management including document reviews on medical response procedures and inspections of equipment and facilities. REM preparedness of nuclear or radiologic facilities has been improved with systematic implementation of processes contained in the regulation. In particular, the medical care system of licensees has become firmly coordinated in the REM network at the national level, which has enhanced their abilities by providing adequate medical personnel and facilities. This legal regulation service has contributed to preparing the actual medical emergency response for unexpected accidents and should ultimately secure the occupational safety for workers in radiation facilities.