Other than in childhood, intussusception is unusual and nearly always caused by a structural and well demonstrable lesion. In contrast with the colon tract, the incidence of primary malignancies in the small bowel is very low. We report the case of a 51-year-old man presenting with jejunal intussusception due to a primary adenocarcinoma. To our knowledge, only a few similar cases have been reported in the literature to date. The patient was referred to our division for bowel obstruction. A CT scan showed a jejunal intussusception and surgical exploration was hence considered. At laparotomy, jejunal intussusception located just after the ligament of Treitz due to a polypoid lesion was confirmed and resection of the first jejunal loop was carried out. Histological examination of the specimen resulted in a diagnosis of a primary adenocarcinoma of the small bowel. In adult intestinal intussusception, resection without reduction is considered the optimal management if an underlying primary malignancy cannot be excluded.