Although vascular malformations have been found in every organ, hemangioma of the colon and rectum are rare. Misdiagnosis often occurs because of lack of awareness of classic clinical features. We report a case of hemangioma involving the rectum. This 17-years-old man presented with intermittent abdominal pain for one year. CT scanning revealed a large mass occupies the lower abdomen and pelvic cavity. A nonhomogeneous and subtle enhancement of the lesion was noticed after contrast administration.