PURPOSE: To describe the MR imaging findings of lumbar Scheuermann's disease and to determine therelationship between various MR imaging findings of this disease and disk pathologies. MATERIALS AND METHODS: Weretrospectively evaluated the MR imaging findings of 13 patients under the age of 20 with lumbar Scheuermann'sdisease. One hundred and four vertebral bodies and 91 intervertebral disks were included in the study. The imagingfindings were analyzed with particular emphasis on the wedging of vertebral bodies, Schmorl's nodes, and theheight of intervertebral disks. The relationship between these findings and disk degeneration or herniation wasevaluated. RESULTS: Lumbar Scheuermann's disease was classified into two types according to Blumenthal'sclassification. Seven patients were type I and six were type II. Disk degeneration and herniation were identifiedin 28.6% (26/91) and 20.9% (19/91), respectively, of intervertebral disks. In type I, wedging of the vertebralbodies was noted in 48.2% of cases(27/56) and degeneration and herniation of adjacent disks were identified in24.1% (7/29) and 13.8% (4/29), respectively. Central Schmorl's nodes were identified in 29.5% (33/112) ofend-plates and degeneration and herniation of adjacent disks in 34.8% (8/23) and 17.4% (4/23), respectively. Intype II, anterior Schmorl's nodes were found in 11.5% (11/96) of end-plates and degeneration and herniation ofadjacent disks in 100% (10/10) and 70% (7/10), respectively. Decreased height of intervertebral disks was notedadjacent to the anterior Schmorl's nodes ; all were related to disk degeneration and 70% (7/10) to diskherniation. There was statistically significant correlation between anterior Schmorl's node, decreased height ofintervertebral disk and adjacent disk pathologies (p<0.05), but wedged vertebra and central Schmorl's node werenot related to disk pathologies (p>0.05). CONCLUSION: In lumbar Scheuermann's disease, anterior Schmorl's nodeand decreased height of an intervertebral disk are related to disk degeneration and herniation. MR is useful forthe evaluation of disk pathologies as well as changes in vertebral bodies.