Oral corticosteroids have adverse effects on bone density and metabolism. With the increased use of inhaled corticosteroids together with the use of higher doses for the treatment of asthma, the long-term effects of inhaled corticosteroids on bone metabolism and density must be evaluated. This article discusses the markers of bone resorption and formation together with techniques used to measure cortical and trabecular bone density. The effects of inhaled corticosteroids on bone density and metabolism as determined by these techniques are described in detail. Overall, inhaled corticosteroids are extremely safe, even at high doses, with the long-term risk of bone loss being extremely small compared with oral corticosteroids. In particular, fluticasone propionate at the recommended doses appears to be free of effects on bone density and metabolism. Finally, the use of inhaled corticosteroids results in the control of asthma, allowing patients to exercise, which itself improves bone density and protects against osteoporosis.