CT scanning of the lumbar spine is in its infancy. Nevertheless, it has had a remarkable effect on the way we evaluate and treat patients. The principal advantages are the following: (1) If the scan alone in the diagnostic work-up of patients with lumbar disc herniation and correlative neurologic deficit. (2) The CT scan aids in the screening of patients with back and leg pain who did not have a neurologic deficit. It may determine the need for further studies such as myelography. (3) CT has become helpful in the evaluation of patients with lumbar spinal stenosis and may replace myelography when greater experience is garnered. (4) CT is of great value in the evaluation of the lumbar spine previously operated on and may provide diagnostic information unavailable on the myelogram because of dural scar formation, arachnoiditis, and so on. (5) Future comparative studies probably will indicate greater accuracy with CT scanning than with myelography, and consequently, the overall diagnostic acumen in the treatment of patients with lumbar spine disease will be improved.