POSTBULBAR peptic ulcers comprise 5% to 10% of all duodenal ulcers. They often present diagnostic and therapeutic problems which are quite different from the usual bulbar ulcer. Ninety-eight percent of postbulbar ulcers occur in the first and second portions of the duodenum and are usually on the posteromedial wall. Characteristic peptic-ulcer pain is the most common symptom. The pain, however, frequently radiates to the back and is often intractable.1-5 Hemorrhage is two to three times more common than in bulbar ulcers, is more severe, and less amenable to medical therapy.1,3,4,6,7 Perforation with peritoneal contamination is a rare complication of postbulbar ulcers, since they usually penetrate into adjacent organs.2-4 This is the case report of a perforated postbulbar ulcer which presented as a retroperitoneal retrocecal abscess. Report of Case A 62-year-old Negro man was admitted to the surgical service on May 20, 1963, with a 24-hour history of