The present study compared the bronchodilating effect of inhalation from the Turbuhaler (0.5 mg terbutaline x 2) with the effect of inhalation from the chlorofluorocarbon (CFC) inhaler (0.25 mg terbutaline x 4) in children aged 9-17 years with reproducible, exercise-induced asthma (EIA). The treatments were given on two occasions, 5 min apart (terbutaline 0.5 mg + 0.5 mg). The study was performed as a double-blind, double-dummy, and placebo-controlled trial in 12 asthmatic children. The study was conducted on three separate days. The bronchoconstriction was induced by steady running on a treadmill. Forced expiratory volume in 1 s (FEV1.0), vital capacity (VC), and volume of trapped gas (VTG) were measured before and after the exercise test and after treatment. The study showed that the same amount of terbutaline inhaled from the Turbuhaler or from a CFC inhaler is equally effective for reversing EIA, and that the Turbuhaler is possibly more effective for treating spasm in small airways.