Inhaled corticosteroids (ICS) in dosages above 1,000 micrograms/d may influence parameters of bone metabolism. Fluticasone propionate (FP) is a new ICS with a higher clinical potency than beclomethasone dipropionate (BDP) combined with negligible oral bioavailability. The aim of this study was to evaluate the effects of FP and BDP in clinically equipotent dosages on indices of bone metabolism and morning cortisol. FP 750 micrograms/d and BDP 1,500 micrograms/d were compared in a randomized, double-blind, crossover study consisting of two 6-wk treatment periods, each preceded by a 3-wk single-blind placebo period. Twenty-one nonsmoking asthmatic completed the study. FP had the same effect on FEV1 and peak expiratory flow as the double dose of BDP. Both treatments did not change morning cortisol. BDP decreased both osteocalcin and procollagen type 1 carboxyterminal propeptide, indices of bone formation, significantly by 18.5 and 21.9%, respectively. In contrast, FP did not change any variable of bone formation. FP and BDP did not increase type 1 collagen carboxyterminal telopeptide and deoxypyridinoline crosslinks, both markers of bone resorption. In changes in parameters of bone metabolism indicate adverse effects on bone quality in the long term, FP may offer an advantage over BDP.