Summary The cost-effectiveness of strontium ranelate was compared to no treatment in UK women using the FRAX® algorithm for fracture risk assessment. At a willingness-to-pay of £30,000 per quality-adjusted life-year (QALY), strontium ranelate was generally cost-effective in women with prior fracture at the threshold of osteoporosis from an age of 65 years. Introduction The objectives of the study were to estimate the cost-effectiveness of strontium ranelate in the UK for the treatment of osteoporosis and to establish intervention thresholds for treatment using the FRAX® tool. Methods The cost-effectiveness of strontium ranelate was compared to no treatment in postmenopausal women with clinical risk factors for fracture using a lifetime simulation model based on Markov cohort methodology that incorporated the features of FRAX®. Results At a threshold of £30,000 per QALY, strontium ranelate was generally cost-effective in women from an age of 65 years with prior fracture at the threshold of osteoporosis (i.e., a T-score of −2.5 SD) and in women with a prior fracture (and no information on bone mineral density) from the age of 65 years. At a threshold of £20,000, strontium ranelate became cost-effective at a 10-year fracture probability of 25.7% and at 16.9% with a threshold of £30,000 for a QALY. Conclusions Strontium ranelate is a cost-effective agent for the treatment of established osteoporosis in women over the age of 65 years. Cost-effective scenarios were also found for the prevention and treatment of fractures associated with osteoporosis, in younger women with additional clinical risk factors.