This report summarizes the discussion of a three-day seminar on endoscopic retrograde sphincterotomy (ERS). Before the seminar a survey of the experience of 21 centers was collected. There were 1250 patients in whom ERS was attempted. It was successful in 89%. The 137 failures were primarily related to large stones or to difficulty in positioning the papillotome. The indications were for common duct stones in 1106 (88.5%), papillary stenosis in 126 (10%), and miscellaneous in 18 (1.5%). The discussions at the seminar revealed marked variation in some aspects of individual techniques. The authors have described indications, contraindications, technique, and complications with an attempt to indicate where concensus was reached. The numerous questions and problems with the procedure are described. ERS has merit, but its precise role in clinical medicine remains to be defined.