The bronchodilator effects of inhaled dry salbutamol powder (50, 100, 200 and 400 μg) have been compared in ten asthmatic patients with those of aerosolized salbutamol (200 μg) delivered from a standard pressurized inhaler. A dose of salbutamol powder (400 μg) produced greater bronchodilatation than 50, 100 or 200 μg of powder, but there was no significant difference between 400 μg of powder and 200 μg of aerosolized salbutamol. Powder administered by Rotahaler is well tolerated and offers several advantages over the pressurized aerosol canister.