Spinal stenosis is a localized narrowing of spinal canal due to strurctural abnormalities. Its symptoms are obscure, and characterized by chronic, poorly localized, bilateral nerve root compression signs. Computerized tomography(CT) has been accepted as almost an absolute diagnostic method for spinal stenosis after its application in the orthopedic field. During the period of 2 years, from March 1982 to March 1984, 26 cases of spinal stenosis were treated surgically after botlt CT scanning and myelography. We obtained following results about advantage of CT scanning in spinal stenosis. 1. Myelography showed following findings: Hourglass defect 9, Complete block 8, Unilateral focal defect 4, Uniform narrowing 1, Mixed 2, Negative finding 2. Myelographic finding was not specific for spinal stenosis and diagnostic accuracy was inferior to CT. 2. The type of spinal stenosis was identified by CT scan finding. Of 26 cases, 21 cases were degenerative spinal stenosis, of which central stenosis was present in 7 cases, and lateral stenosis was present in all cases. The remaining 5 cases were combined type, and both central and lateral stenosis were present in all cases. 3. The diagnostic accuracy,in localizing the level of stenosis was 61.5% by myelography, and 96.2% by CT scan. CT was especially superior to myelography in the localization of the multi-segmental stenosis. 4. CT gives valuable information about extent and degree of stenosis, especially lateral recess stenosis, thus helping the surgeon to decide on the extent of decompressive lamininectomy preoperatively.