To define the clinical significance of delayed postsphincterotomy hemorrhage, we reviewed 476 consecutive ERCP procedures performed over a three-year period. Of 250 patients who underwent endoscopic sphincterotomy (ES), five (2%) developed postprocedure hemorrhage, two of whom had immediate, self-limited bleeding that resolved after endoscopic injection of epinephrine and did not require transfusion. The other three had delayed hemorrhage characterized by: onset 20-48 hr after the procedure, melena without hematemesis as the index clinical manifestation of bleeding, and atraumatic balloon extraction of common duct stones. Transfusion of 2-6 units of packed erythrocytes was necessary in each and one patient required surgical hemostasis. Delayed hemorrhage following ERS is an important, frequently severe complication to remember when contemplating performing ERS as an outpatient procedure.