OBJECTIVE AND IMPORTANCEIntramedullary tumors affect a small but significant segment of patients with spinal cord tumors. Intramedullary teratomas are rare entities that are usually located in the sacrococcygeal region. Although some reports claim that diagnostic studies can exactly predict the nature of intramedullary tumors, this case report demonstrates the lack of preoperative diagnostic specificity. Therefore, the aim of surgery should be radical extirpation whenever possible.CLINICAL PRESENTATIONA case report of a thoracolumbar intramedullary teratoma is presented. This young male patient displayed urinary retention and motor deficits. Computed tomographic and magnetic resonance imaging examination revealed an intramedullary tumor; however, the exact nature of the tumor could not be determined preoperatively. The literature concerning these tumors is extensively reviewed.INTERVENTIONDuring surgery, a multicystic tumor was found at the base of the filum terminale, which was resected as far as possible.CONCLUSIONIt is concluded that surgery should be the first choice for treatment. More aggressive teratomas are found in intramedullary locations, especially in children, emphasizing the importance of radical tumor resection. The use of adjuvant chemo- or radiotherapy should be explicitly substantiated for the nonbenign teratoma group.