Schwannoma is a benign tumor derived from Schwann cells which are usually found in the head, neck, trunk, upper and lower extremities, and rarely in the thoracolumbar junction. Also, osteopetrosis is an idiopathic genetic skeletal disease that rarely occurs. Most reports of osteopetrosis are about long bone fractures, but spinal tumor in osteopetrosis has been rarely reported. Furthermore, there is no report about thoracolumbar intradural Schwannoma and its treatment in patient with osteopetrosis. Thus, we report the clinical results of a thoracolumbar Schwannoma in a 36 year-old female osteopetrotic patient who had progressive weakness, and dysesthesia of the left lower limb. The patient underwent laminectomy and total excision of tumor through a posterior approach, and a favorable clinical outcome was achieved.