We herein report the rare complication of sepsis caused by endoscopic clipping for colonic diverticular bleeding. A 78-year-old man with a 12-h history of near syncope and painless hematochezia was admitted to our hospital. Following the transfusion of 4 U of blood and continued hematochezia, a colonoscopy was performed. Active bleeding was seen as continuous arterial spurting from a single diverticulum located in the middle ascending colon. This diverticulum was seamed by four endoclips. The next day, the patient became febrile with a temperature of 39.2℃. Laboratory data included a white blood cell count of 18 100/mm3 and a C-reactive protein level of 3.4 mg/dL. He was diagnosed with sepsis since Escherichia coli was detected in the blood culture. Antibiotics were started. Four days later his fever had improved and laboratory data improved 9 d later.