Sarcomatoid carcinoma is a rare form of primitive carcinoma of the small bowel; it is considered a variant of adenocarcinoma, histologically characterized by a typical biphasic pattern with epithelial- and mesenchymal-like cells. Twenty-one cases have been described in the literature, presenting as small bowel obstructions (twenty cases) or superior vena cava syndrome (one case). The authors report the case of a 56 year-old man on immunosuppressive therapy for a heart transplant, who underwent surgery after a history of repeated episodes of melena, anemization and bowel obstruction. The operation brought to light an intraluminal occlusive mass in the distal ileum, associated with other intraluminal neoplasms of different sizes throughout the small bowel. No evidence of mesenteric adenopathies or hepatic metastases were found. Histological examination and immunohistochemical stain showed an anaplastic sarcomatoid carcinoma. The tumor cells showed strong positivity for cytokeratin and vimentin, and negativity for CD117 and CD34, as well as for all other characteristic markers of mesenchymal tumors. Early diagnosis is usually very difficult, due to the lack of any stereotyped clinical expression and the difficult to study the small bowel. Small-bowel barium follow-through or video capsule endoscopy can be helpful. In most cases, an emergency surgical operation is performed without a clear preoperative diagnosis. The case report is completed by a review of the literature.