Bisphosphonates are potent inhibitors of bone resorption that have come to play a prominent role in the prevention and treatment of various forms of osteoporosis and other metabolic bone disorders. Therapy in women with osteoporosis and at high fracture risk substantially reduces the incidence of vertebral and non-vertebral fractures. In younger postmenopausal women, bisphosphonates are attractive alternatives to oestrogen to prevent bone loss and the subsequent development of osteoporosis. Bisphosphonates have recently become the treatment of choice to prevent and treat the skeletal consequences of chronic corticosteroid therapy. When administered appropriately, these drugs are very well tolerated and have an excellent safety profile. The challenges now to clinicians are to identify the patients for whom bisphosphonate therapy is indicated and to devise dosing and monitoring strategies to enhance the long-term adherence to therapy required to realise the full benefits of these treatments.