Abstract A 31‐year‐old man developed massive walled‐off necrosis extending into the pelvic cavity following severe acute alcoholic pancreatitis. Endoscopic ultrasound‐guided fistula drainage was performed using a lumen‐apposing metal stent, but this was insufficiently effective, and endoscopic necrosectomy was also performed, after which the patient improved. Percutaneous drainage and surgery are other options for the treatment of walled‐off necrosis extending into the pelvic cavity, but a valuable case in which the patient improved with endoscopic treatment alone is presented.