The bone mineral content of 109 excised lumbar vertebrae from 21 (aged 34-74 yr) and 15 men (aged 31-79 yr) was determined with dual photon absorptiometry. It was correlated with the age, height and weight of the subjects and with the body weight above each vertebra. No correlation was found between the bone mineral content and the lumbar spine score of Barnett and Nordin. The bone mineral content determined with dual photon absorptiometry was also correlated with the weight of fresh and ashed bone cubes removed from the interior of 40 of the aforementioned vertebrae selected at random. The bone mineral content decreased with increasing age and at a similar rate within the ages studied in both sexes. Pathologic demineralization in the elderly could be the result of low bone mineral content early in life, and more frequently so in female vertebrae.