In a cadaver-derived skeletal collection of 1,384 thoracolumbar spinal columns, 103 (7.4%) individuals with vertebral changes of Scheuermann's kyphosis were identified. Anterior extension of the vertebral specimens was noted in 94% of affected specimens. No evidence of osteoporosis was noted by single-photon absorptiometric analysis in the affected sample compared with a normal control group. Biopsy specimens from two immature patients obtained at surgery suggested disorganized endochondral ossification similar to that noted in Blount's disease. It was concluded that increased pressure on the anterior margin of the centrum is responsible for histologic and morphologic changes of Scheurermann's kyphosis.