PURPOSE: To evaluate the radiologic manifestations of the rectal leiomyosarcoma. MATERIALS AND METHODS: We reviewed CT and barium study of 2 cases of rectal leiomyosarcoma, which were operated and pathologically proved. RESULTS: In both cases colon studies showed a huge smooth marginated filling defect in the rectum. Precontrast CT scans showed a well-circumscribed, slightly Iobulated, inhomogeneous mass without calcification. Postcontrast scans showed minimal enhancement with internal low-density areas. In pathologic specimens there were large areas of necrosis and hemorrhage in the masses. Pericolic fat infiltration, lymph node metastasis, or distant metastasis were not detected. CONCLUSION: Leiomyosarcoma is rarely developed in the rectum, but general radiologic findings are similar to that of other part of the gastrointestinal tracts except for the tendency of intraluminal growth due to narrow pelvic space.