Inhaled corticosteroids have become the mainstay of maintenance treatment in asthma in adults, and they are also being advocated for early use in children. The systemic side effects of inhaled steroids are much less than those from systemic steroids needed for comparable asthma control. Long term use of systemic corticosteroids is known to cause osteoporosis, and the risks from inhaled therapy are currently under study. There are reports of changes in biochemical parameters of bone meatabolism due to inhaled corticosteroids, suggesting depression of bone formation by osteoblasts and more controversially, an increase in bone resorption. However, the significance of biochemical changes in relation to bone mass and architecture is not known. Cross-sectional studies of bone mass suggest that dosages of more than 1 mg daily in adults may be associated with a decrease in bone mineral density. Longitudinal studies are needed to confirm the findings and define more clearly the profile and risk factors of osteopenia due to inhaled therapy. Current data in children show that inhaled corticosteroid in the usual therapeutic dose range has no detrimental effect on long term statural growth, while effects on peak bone mass are not yet known. The magnitude of measurable adverse effects were found to be dose-dependent, hence, the use of a minimum effective dose is recommended. Patients on inhaled corticosteroid therapy should be advised to have a daily calcium intake of 1000 to 1500 mg and to maintain physiological doses of Vitamin D. Physical activity should be encouraged and oestrogen replacement therapy in postmenopausal women considered.