The relationship between the amount of bone in the lumbar spine and ligamentous properties has not been studied. This article reports the tensile structural properties of bone-ligament-bone preparations of the anterior longitudinal ligament from 15 human lumbar spine segments. Significant correlations were found between the vertebral bone mineral content expressed as BMC(g/cm) and BMA (g/cm2) and BMD (g/cm3) and the structural properties of the vertebral bone-anterior longitudinal ligament-bone complex determined at yield and failure. These findings suggest that the amount of bone tissue in the spine may be functionally related to structural properties of the spinal ligaments.