A rare case of colo-colic intussusception caused by a adenomatous polyp in a 13-year-old male is presented. The patient admitted to the hospital complaining of abdominal pain and bloody stool. Abdominal plain X-ray examination revealed a filling defect in the descending colon. Ultrasonography showed a so called target sign in the same portion indicating a colo-colic intussusception. The intussusception was reduced successfully with a hydrostatic pressure. A barium enema demonstrated a polyp in the descending colon serving as a leading point. The following day, the polyp was removed by colonoscopic polypectomy. Pathological diagnosis was tubular adenoma.