BACKGROUND Endoscopic migration of plastic biliary stents is performed by endoscopic retrograde cholangiopancreatography (ERCP) for biliary and pancreatic diseases. This plays an increasingly important role. Intestinal perforation caused by stent migration is one of the complications. Although sigmoid colon perforation caused by stent migration is rare, it can be life-threatening. This case shows us that we should increase awareness of sudden abdominal pain after ERCP. METHODS We provide a review of the clinical manifestations, imaging data of this case, and the literature related to the perforation caused by stent migration. RESULTS A male patient had a history of choledocholithiasis, cholecystolithiasis, and biliary pancreatitis treated with ERCP and a pancreatic stent. After the operation, the patient developed cholangitis and was treated with ERCP and a plastic biliary stent. This patient was admitted to the emergency department with sudden lower abdominal pain. A CT scan showed sigmoid colon perforation by a foreign body and infra-diaphragmatic free air. An emergency surgery confirmed that the stent had caused the perforation. The patient was then treated with sigmoid colectomy and sigmoidostomy. CONCLUSIONS Biliary stent migration after ERCP is rare, but intestinal perforation caused by migration should be considered in cases of abdominal pain of unknown cause.