Adult intussusception is a rare and serious medical condition that is fatal if not treated with surgery. This condition is mainly caused by a leading lesion, and is manifested by intestinal obstruction clinically. Here, we present a case of a 44-year old patient with duodenal-duodenal intussusception and a family history of colon cancer. The preoperative diagnosis of duodenal-duodenal intussusception was performed by panendoscopy, abdominal ultrasonography and an abdominal computer tomographic scan. The patient was diagnosed as having duodenalduodenal intussusception as a result of a leading hamartoma.