Radiotherapy (RT) is a cancer treatment that has been widely applied to cancer patients. However, this treatment could induce radiation skin injuries that affect the quality of life of patients. The radiation-induced ulcer is a late-stage complication of radiation burns that could not be self-limited. This chapter summarizes current knowledge relating to RT-induced skin reactions, including epidemiology, pathophysiology, diagnosis, prevention, and management. Additionally, the author also presents the experience of treating RT-induced ulcers by surgical treatments that were shown to give satisfactory results on patients.