A 95-year-old woman admitted to our hospital for senile dementia showed hemorrhage from rectum, and colonoscopy was performed. Circumferential hemorrhagic concomitant nodular aggregated tumor was found spreading from just above denticulate line to the lower rectum. She has a past history of rectal tumor, for which endoscopic mucosal resection was performed in 1998. Based on the biopsy finding, the tumor was diagnosed as a highly differentiated adenocarcinoma, and the hemorrhage was speculated to be induced by local recurrence. Considering patient's very high age and poor risks, argon plasma coagulation (APC) therapy succeeded in controlling the hemorrhage. After the therapy, the tumor itself showed no tendency to grow, and clinical course remained favorable for 10 months up to now. APC therapy is considered useful for the hemorrhagic tumors in the gastrointestinal tract in the highly aged patients with high risk.