The objective of this double-blind, randomized, placebo-controlled, parallel-group study was to compare the pharmacodynamic effects and safety of beclometasone dipropionate (BDP) given by nebulization or metered-dose inhalation in adult patients with asthma. Following a 1-week run-in period, 40 patients, aged 18-60 years, with intermittent bronchial asthma were randomized to one of four treatment groups for 3 weeks (n = 10 in each group): beclometasone dipropionate (BDP) suspension for nebulization 1,600 microg day(-1) b.i.d. via a nebulizer, BDP suspension for nebulization 3,200 microg day(-1) b.i.d. via a nebulizer, BDP 800 microg day(-1) b.i.d. via a metered-dose inhaler (MDI) plus spacer, or placebo. At study end, comparable effects were reported for all active treatment groups on the primary pharmacodynamic endpoint of FEV1 in response to methacholine bronchial provocation testing, with a statistically significant improvement shown in the BDP 3,200 microg day(-1) suspension for nebulization group compared with pre-treatment for other parameters, including FEV1 and peak expiratory flow rates. All treatments were comparable. All treatments were equally well tolerated. No significant effects on cortisol levels were reported in any of the treatment groups.