Based on the empirical data of more than 2500 examinations we report on the technique of the endoscopic retrograde cholangio- and pancreaticography (ERCP), the endoscopic papillotomy (EPT) with calculus extraction and also the percutaneus transhepatic cholangiography (PTC) from the radiologic point of view. The essential tasks of the radiologist are the clarifying of the position of the probe, the quick diagnosis and the making of valid x-ray photographs. For this purpose the knowledge about an optimal technique of examination is the prerequisite. By this the experienced radiologist is an important partner of the gastroenterologist. He helps to avoid complications for the patient.