A dose-ranging study and a 12-week treatment study were conducted in children with asthma, aged 4 to 12 years, to assess the efficacy and safety of albuterol inhaled as either an aerosol or as dry powder. Both studies were double-blind and placebo-controlled with randomized assignment to treatment. The dose-ranging study in 30 patients indicated that similar single doses of albuterol aerosol and powder had comparable effects with the intermediate doses (i.e., 180 micrograms of aerosol and 200 micrograms of powder) providing effective bronchodilation with minimal adverse effects. In the subsequent 12-week, parallel-group study, 204 children received albuterol as either aerosol, 180 micrograms, or powder, 200 micrograms four times a day. Both formulations were equally effective with no untoward cardiovascular effects and only one incident of mild tremor. Among those children who expressed a preference for one of the delivery systems, significantly more children preferred the powder (44% versus 26%, p less than 0.01). Albuterol taken four times a day as either aerosol or dry powder is both effective and well tolerated in children with asthma.