A COMMON surgical concept is that a duodenal diverticulum bears no relationship to a patient's symptomatology and is usually found incidentally at the time of gastrointestinal x-ray examination. Moreover, many writers have repeatedly emphasized that its clinical significance is not great because a diverticulum rarely becomes inflamed and does not lead to serious disease. While this thinking is generally true, a striking exception has recently been encountered in a patient who presented with a ruptured duodenal diverticulum, ruptured by an impacted diverticulum stone or enterolith. This prompted an evaluation of the complications of duodenal diverticulitis that are of surgical interest. Report of Case A 69-year-old white, female, retired school-teacher was admitted to the hospital in June of 1964, because of intense, generalized abdominal pain of seven hours' duration. The patient had been ill for five days with nausea, vomiting, and abdominal pain, particularly in the right upper quadrant. From the