During a 4-year period (1978-1982), 206 patients were examined with endoscopic retrograde cholangiopancreatography (ERCP) because of jaundice with suspected biliary obstruction. The total of examinations was 223. Duodenoscopy with ERCP gave a positive primary diagnosis in 160 cases (78%), six (4%) of which later proved to be incorrect. Extrahepatic obstruction could be excluded in 16 patients with normal cholangiogram (8%). Clinically relevant information thus was obtained in 176 cases (85%). The main cause of extrahepatic obstruction was common bile duct stone(s), which were found in 73 patients. Immediate endoscopic sphincterotomy was performed in 64 of them and cleared the duct of stones in 54 (84%). Benign stenosis of the ampulla of Vater was relieved with endoscopic sphincterotomy in six patients. Malignant bile duct obstruction was diagnosed in 56 patients, and in three of them an endoprosthesis for internal drainage of the biliary tract was endoscopically inserted. Immediate complications after ERCP without endoscopic sphincterotomy occurred in 5 of 136 patients (4%), one of whom died. The authors conclude that ERCP is a rapid, reliable and safe diagnostic method in patients with extrahepatic biliary obstruction.