A 58-year-old man with advanced cholangiocarcinoma used diclofenac sodium suppository up to 200 mg in order to relieve right hypochondralgia and fever. One month after continuous NSAID usage, he was hospitalize to our hospital because of bloody diarrhea followed by massive rectal bleeding. Urgent endoscopic examination revealed irregular shaped multiple rectal ulcers, indicating a diagnosis of sodium suppository-induced acute hemorrhagic rectal ulcer. Bowel rest and GeloformTM tamponade achieved temporal hemostasis. However, rectal bleeding recurred and total amount of hemorrhage reached to 6,000 ml. We performed colonoscopy-guided argon plasma coagulation (APC) to the hemorrhagic rectal ulcers two times and complete hemostasis was achieved. Since APC is able to coagulate digestive mucosa of target widely and safely, APC is considered as an effective endoscopic hemosatatic procedure to acute hemorrhagic rectal ulcer.