Economic evaluations are increasingly being used by decision-makers to estimate the cost-effectiveness of interventions. Major changes have recently occurred in the treatment of osteoporosis. The development of a valid economic model (Markov) in the field of osteoporosis is discussed, as well as these limitations. Intervention, such hip protectors, calcium and vitamin D, bisphosphonates, hormonal replacement therapy, SERMs, strontium ranélate, analogue of parathyroid hormone are analysed in the light of cost-effectiveness analyses.