Hemorrhagic radiation proctosigmoiditis is a serious complication of pelvic radiation therapy. Pharmacotherapy is generally ineffective in the treatment of chronic radiation proctitis. Argon plasma coagulation is an effective, safe and well-tolerated therapy option for radiation proctitis. We report a case of hemorrhagic radiation proctosigmoiditis treated successfully with Argon plasma coagulation. We used argon plasma coagulation for mucosal coagulation in painting pattern set at 1.5 L/min and 60 W. After five therapy sessions with argon plasma coagulation, the patient's rectal bleeding and anemia resolved. After four months of argon plasma coagulation therapy, the patient is well and her endoscopic examination showed remarkable improvement of the vascular lesions. Blood transfusion requirement was resolved after therapy, and hemoglobin level increased from 8.2 g/dl to 11.5 g/dl. Argon plasma coagulation therapy may be useful as alternative treatment for hemorrhagic radiation proctitis. Future prospective controlled trials are necessary to confirm the efficacy of argon plasma coagulation in the treatment of radiation proctitis.