Sacrococcygeal teratomas are rare congenital tumors, generally discovered at birth. These tumors are seldom observed in children. Radical resection must be performed to avoid potentially malignant recurrence even if the primary lesion is benign. We report a case in an 8-year-old girl who did not have a past medical history. Since the age of 2 years, she presented a progressive sacral tumefaction with no neurological deficit. The MRI showed a large sacrococcygeal cyst in hypointense-signal T1-weighted imaging with no contrast enhancement, and a hyperintense signal in T2-weighted imaging. At surgery, the tumor was totally removed. The intraoperative aspect was that of a viscous cyst. The histological study showed a sacrococcygeal teratoma.