The appendix has been reported to be a very rare leading point in intussusception. Therefore, preoperative diagnosis can rarely be made. We experienced one case of appendicocecal intussusception in a 2-year-old girl. An air contrast study done during air reduction suggested a cecal mass, and a saline filled sonogram showed a polypoid lesion in the cecum. The lesion turned out to be an intussuscepted appendix in appendicocecal intussusception.