We describe a 54-year-old man who was referred with the diagnosis of adenocarcinoma of the angle of Treitz and treated with the use of a duodenojejunal segmentary resection. After a review of the literature, we emphasize the difficulty of making an early diagnosis and discuss the most appropriate surgical treatment of tumors of the angle of Treitz. The better prognosis of these neoplasms compared with those of the proximal duodenum can be supported by some embryological findings observed from a different research project currently in progress.