The diagnostic and therapeutic role of ERCP in 42 patients ranging from 1 to 19 years of age is discussed. ERCP provided useful additional information in 15 patients with biliary tract disease, 15 patients with pancreatic disease, and 9 patients with abdominal pain. The appropriate duct was cannulated in 95% of cases. Mild pancreatitis occurred in two patients after ERCP. Endoscopic papillotomy was successful in five patients. ERCP plays an important part in the investigation of unexplained biliary tract and pancreatic disease. It rarely demonstrates abnormal pathology in patients with otherwise unexplained abdominal pain.