An approach to the diagnosis and follow-up of patients with osteoporosis is described. A system of classification of vertebral fractures is outlined, and the relative merits of different techniques for bone mineral density are discussed. The importance of identifying factors that accelerate bone loss is stressed. The value of optimizing treatment by using bone histomorphometry and biochemical markers to measure bone turnover is discussed. Finally a plan is outlined for the timing of follow-up bone mineral density measurements.