One of the most common benign tumors of bone is the osteochondroma which is a cartilage-capped bony projection on the surface of a bone. It may occur in any bone that has been performed from cartilage, but the most common locations are the long bone at the metaphyseal region of the most active growth cartilage, that is, the lower end of femur, the upper end of the tibia, and the upper end of the humerus. Other bones often involved are the ilium, scapula, fibula, and phalanges of hands and feet. But, the vertebral column is very rare location for osteochondroma. Only one case of osteochondroma involving the lumbar spine has been previously reported in Korea. We report an unusual case of osteochondroma arising from the left lamina and inferior articular process of the 3rd lumbar spine causing spinal cord compression.