Morphometric measurements of the thoracic and lumbar vertebrae were carried out on spinal radiographs of 150 normal women. A normal range was established for each individual vertebra. There was no change in the anterior height of the thoracic or lumbar vertebrae with age but there was a small significant decrease in the posterior height of the lumbar vertebrae with age. This is unlike the pattern seen in osteoporotics in whom a decrease in anterior height of the vertebrae is the first clinical manifestation of spinal osteoporosis. At the present time diagnosis of an osteoporotic spinal fracture is usually based on a subjective decision. Normative data for the vertebral dimensions should help improve the accuracy of diagnosis.