Adult intussusception is a rare condition, unlike in children. Ihere is an identifiable bowel lesion as a leading point in most of cases. Retrospectively we reviewed 22 patients with adult intussusception, and analyzed CT scans of 13 patients during the last 5 years. Twenty of the 22 patients had various causes of intussusception and 7 patients were associated with primary malignancy, 5 patients with benign tumor, and 4 patients with adhesive band. CT scans of 13 cases all showed characteristic target appearance or sausage-like soft tissue mass within the bowel, suggesting intussusception. In eleven of the 13 patients(84.6%) an intussuscepting mass was identified on CT scan as the lead point. Specific diagnosis for the cause of intussusception could be made by CT in four of 13 cases (three lipomas and one mucocele). In conclusion, CT is useful not only for the diagnosis but also for the evaluation of the leading causes of intussusception. Especially, CT could determined the exact cause of intussusception in cases of lipoma and mucocele.