Endoscopic retrograde cholangiopancreatography (ERCP) is a commonly used method in the diagnosis and treatment of biliary and pancreatic channel diseases. Perforation is one of the rare but most feared complications of endoscopic retrograde cholangiopancreatography. A 90-year-old male patient was admitted to the emergency department with dyspnea. According to the anamnesis obtained from the patient, the patient's shortness of breath was long-lasting, but he had complaints of new onset abdominal pain. When the patient's anamnesis was deepened, it was learned that he underwent ERCP for choledocholithiasis 10 days ago. In the physical examination, the patient had severe pain in the right upper quadrant of the abdomen. Other system examination findings were normal. In the patient's hemogram, WBC: 20,7 * 10 ^ 9 / L and biochemical parameters, creatinine were 2.35 mg / dL, but other biochemical parameters were normal. The CRP of the patient was 15.8 mg / dL (normal range0.35). Abdominal ultrasonography was requested in accordance with physical examination and laboratory values. The patient's abdominal ultrasonography revealed that the gallbladder was of normal size, wall thickness and echo were normal, and a large number of stone echoes and common bile duct dilated (7 mm). Then the patient with CRF was asked for noncontrast abdominal CT. Noncontrast abdominal CT revealed suspicious free air densities in the paraduodenal area and was first evaluated in favor of intra-retroperitoneal abscess secondary to duodenum perforation. The patient was referred to the general surgery intensive care unit. The diagnosis of duodenal perforation after ERCP is usually based on physical examination findings, fluroscopic imaging and in some cases by computed tomography imaging. The treatment of these perforations should still be discussed. Conservative treatment methods are preferred in most patients. However, it requires careful observation and early surgical consultation, as the result may be poor in patients who are unable to receive fast and appropriate treatment. Perforation should be kept in mind in patients with abdominal pain starting with endoscopy and ERCP. A careful history and physical examination in emergency departments can be diagnosed by direct radiography and computed tomography. Most of the cases diagnosed early can be followed by conservative treatment. Delayed diagnosis and treatment may have adverse consequences such as sepsis and death, so early surgical consultation should be sought.