Ectopic pancreas is commonly located at stomach, duodenum and jejunum. It is a relatively rare entity and is usually of no clinical importance which especially is a very rare source of massive upper gastrointestinal bleeding. We have recently experienced a case of an ectopic pancreas in the second portion of the duodenum which was proven to be a source of massive gastrointestinal bleeding by duodenoscopy and was confirmed by surgical exploration. (Korean J Gastrointest Endosc 17: 195-199, 1997)