Optimising lifestyle and diet are important in the management of osteoporosis, however, they cannot completely prevent postmenopausal bone loss. Calcium supplementation significantly retards but does not completely arrest bone loss, but several small controlled studies suggest that it reduces fracture incidence. Thiazide diuretics slow bone loss similarly but their effects on fracture incidence remain to be determined. Hormone replacement therapy (HRT) increases or maintains bone density, prevents height loss and prevents vertebral fractures. There is observational evidence that HRT decreases cardiovascular disease and increases the risks of thromboembolic disease and breast cancer. The selective estrogen receptor modulator (SERM) raloxifene also slows postmenopausal bone loss although it is less effective that HRT. It also increases the risk of thromboembolic disease but is associated with a significantly reduced risk of breast cancer. The bisphosphonates are of comparable efficacy to HRT in the prevention of bone loss and have been shown to halve the risk of fractures of the vertebrae, forearm and hip. The maintenance of normal vitamin D (colecalciferol) status is important, particularly in the elderly. HRT, the bisphosphonates and raloxifene are all suitable for use in the prevention of postmenopausal bone loss, but the former 2 are to be preferred in the treatment of established disease. The most comprehensive long term safety data are available for HRT. Clinical trials are underway at present with more potent bisphosphonates which may make possible longer dose intervals and alternative routes of administration. There is a need for an effective bone anabolic factor but those which have been trialled to date have not proceeded because of significant adverse effects.