The incidence of duodenal diverticulum found incidentally during upper gastrointestinal roentgenographicexamination varies between 2% and 5%. The majority of cases occur along the medial aspect of the second portion of the duodenum, within 2.5cm of the ampulla of Vater. The majority of duodenal diverticula are asymptomatic, but insome cases, complications such as diverticulitis, hemorrhage, perforation, and fistula formation occur in thethird and fourth portions of the duodenum. We describe a case of giant diverticulum of the transverse duodenum,revealed by UGI and angiography, massive gastrointestinal bleeding in a 80-year-old patient.