Benign solitary osteochondroma are the most common benign bone tumor, and often arise in the long bone of the extremities about 80% of lesions, particulary about the knee and the upper extremity. In rare cases, the spine is involved. We describe a case in which a solitary sacral osteochondroma compressed the lumbosacral plexus, producing sensory disturbance. The tumor was removed through the anterior midline approach. The excised mass was round, lobulated, measuring 7. 5cm×6cm, pedunculated type and the cartilage cap is complete and is 4mm in thickness.