Rectal carcinoid tumor is relatively rare neoplasm orignated in Kulchitszky cell and clinicians have the difficulties in predicting their malignant potential and in proper treatrnent. The vast majority of rectal carcinoid tumors are benign and can be safely treated by local excision. Lesions larger than 2 cm and invading the muscular wall of the rectum should be considered rnalignant and treated by more radical surgery such as abdominoperineal resection. 3Ve had a case of 35-year-old male patient with a malignant rectal carcinoid tumor 2 cm in the length diagnosed by colonofiberscopy. So we present this case with a review of relevant literatures.