PURPOSE: Chordoma is a rare primary osseous tumor arising from the remnants of the primitive notochord. It occurs once in 2,000,000. It is characterized by its slow growth, high frequency to invade destroy bone by direct extension. We experienced giant sacral chordoma and reconstructed with gluteal advancement flap. METHODS: A 52-year-old woman presented with a 2-years history of gluteal pain. In the biopsy study revealed sacral chordoma. MRI study showed 13 x 12 x 10 cm sized m0cs. We approached anterior and posterior resection and reconstructed with bilateral gluteus maximus advancement flap. RESULTS: After the operation, blader and anal function were slightly decreased. But, 4 months later those were almost fully recovered. There was no significant complication and recurrence after 2-years follow-up. CONCLUSION: Chordoma is characterized by its slow growth, high frequency to invade and destroy bone by direct extension. Wide surgical resection is the only curative procedure. We report a ase of giant sacral chordoma which was successfully treated by anterior and posterior approach and reconstructed with bilateral gluteal advancement flap.