Osteoporosis is: (1) Underrated. Currently costs about 7 billion dollars annually in Australia. Has high morbidity and 2-3-fold increase in risk of death after any major osteoporotic fracture. Genetic factors contribute highly to risk, modified by lifestyle and hormonal factors. (2) Underdiagnosed. Bone density is a good predictor of subsequent risk. Anyone with a low-trauma fracture has osteoporosis unless proven otherwise. Every individual with a low trauma fracture should be investigated for exclusion of underlying osteoporosis and considered for effective treatment to reduce future fracture risk. More than 75% of women and about 90% of men with a high likelihood of osteoporosis are not investigated. (3) Undertreated. More than 75% of those affected are not treated. Effective treatments (eg, hormone replacement therapy, selective oestrogen receptor modifiers and bisphosphonates) reduce fracture risk by 30%-60%. Simple measures like vitamin D and calcium supplementation and use of hip protectors can reduce hip fractures, particularly in institutionalised and housebound elderly people