The authors describe the case of a 49-year-old man with a giant diverticulum of the duodenum, with apparently scarce symptoms, pointed out by gastroscopy and X-ray of the upper gastrointestinal duct with barium meal. The removal of the lesion, obtained after surgical operation, showed a diverticulum with a 6 cm diameter, with signs of diverticulitis; the histological test did not point out is degenerative lesions. A survey of the recent literature on the matter is presented.