Vertical and sagittal diameters from the twelfth thoracic to the third lumbar vertebral body of newborns, children and adolescents were measured on 187 lateral roentgenograms which had been interpreted as normal. An index between the vertical and sagittal diameter (Ivb = v/s) was formed and values with double standard deviations were calculated. The index is significantly higher in the second month of life in D 12 and L 2 than in newborns. After the eighteenth month the index decreases, is stable, and from 4-12 years afterwards rises once more. There exists a sex difference which becomes significant in D 12 and L 1 for 4-12 year old children and in pubertal children. Girls have a higher index than boys, which was explained by higher vertical diameters in girls older than 12 years or taller than 140 cm. and by higher sagittal diameters in boys. At the same time, disk spaces in the embryologically corresponding segment of the investigated vertebral bodies were measured. An index between the disk and the next lower vertebral body height was calculated (Id=d/v). This index decreases significantly after the first month and is almost stable until 12 years when it decreases once more. No significant sex differences were found.