Osteoporosis is an increasing and major public health problem as our population ages. Advances in our understanding of osteoporosis have been facilitated by the advent of accurate and precise methods of bone density measurement. Developments in therapy include transdermal oestrogens, nasal calcitonin and bisphosphonates. The most important principles of management involve maximising bone mass in early adult years and preventing postmenopausal bone loss by oestrogen therapy.