A 57 year- old man with lateral abdominal wall bulging. MRI showed thoracic disk herniation at the T11-T12 level. Needle electromyogram disclosed acute denervation in paraspinal and abdominal muscles innervated from thoracic spinal nerve 11. Eight months later the swelling was reduced significantly. Thoracic disc herniations are rare and three similar cases have been described previously 1).