The clinical use of an ultrasonic probe with the radial scan transducer in the biliopancreatic ducts is reported in 35 patients with biliopancreatic lesions, including 11 cases of bile duct and 5 of pancreatic carcinoma. Two approaches are available for the intraductal scanning of bile and/or pancreatic ducts. One is the percutaneous insertion via a percutaneous transhepatic biliary fistula established for cholangioscopy. The other approach is the transpapillary insertion of the probe via the working channel of the duodenoscope. Using both approaches, ultrasonographic images of the bile duct wall, pancreas head and neighboring major blood vessels could be observed clearly. The extent of bile duct and pancreatic carcinoma could also be visualized. We believe that intraductal scanning using ultrasonic probes is a promising method in the staging of biliopancreatic malignancy.