The authors report two cases of adenocarcinoma of the duodenojejunal angle and remark the rarity of this pathology, the difficulty of making diagnosis peculiar to neoplasm of the small intestine and the difficulty of treatment peculiar to tumours of the duodenum. According to the literature the diagnosis was determined through X-ray films, after traditional endoscopy was inadequate. Surgical treatment is radical, with extensive exeresis procedures (unless the mesenteric upper vessels are infiltrated) since the prognosis of this tumours is good.