MR images obtained in 40 patients with surgically proven lumbar herniated intervertebral disc(HIVD) and/or spinal stenosis were retrsopectively analysed and compared with CT scans, in order to evaluate the MR findings of HIVD and spinal stenosis, and to assess the diagnostic accuracy of MR. The MR imaging was performed on a 2.0T superconducting unit, using multislice spin echo (SE) and gradient echo (GE) techniques. The results were as follows: 1. The texture of vertebral body with spinal stenosis had the tendency to be more heterogeneous than that with HIVD. 2. The signal intensity of the diseased disc was isointense relative to nomal disc in 81%(60/74) and the remainder(19%) was hypointense on both T1 weighted SE and GE images. There was no significant difference in signal intensity amont HICD, HIVD combined with spinal stenosis and spinal stenosis groups, but there was the tendency of lower signal intensity of the diseased disc in patients with severe degenerative change of spine inboth T1 weighted SE image and GE image. 3. The diagnositc accuracy of MR was 92%, which was similar to that of CT.4. T1 weighted SE image appears superior to GE image in evaluatio of most of the structural differentiation, butas for differentiation between lumina and ligamentum flavum, and for the vacuum phenomenon, GE image seems to bebetter than T1 weighted SE image. In conclusion, MR appears to be better than CT as a initial imaging modality in evaluation of the patients with suspected lumbar spinal stenosis of HIVD because MR has the capability of demonstrating rupture of anulus fibrosus in sagittal plane.