Giant sacral schwannoma is a very rare tumor (25 cases reported). The authors report 3 cases of giant sacral schwannoma treated by curettage through posterior approach and discuss symptoms and treatment. These tumors were characterized by their minimal symptoms compared to radiographic findings. Magnetic resonance imaging must be performed in order to detect extraosseous tissue component and intradural invasion. A biopsy was performed to confirm the diagnosis before definitive treatment. Wide resection was proposed by many authors because of the high recurrence rate. We believe that a wide resection is too sever as it causes neurologic sacrifices. A curettage through posterior approach preserves nerve function, and if a local recurrence occurs it remains possible to perform a wide resection. When sacroiliac joint instability is detected, a lumboiliac arthrodesis is indicated. Osteosynthesis could be performed with spine device (using pedicular and iliac screws).