Many studies in which patient's inhaler use technique has been studied have shown that one of the major problems patients have, in using an inhaler correctly, is that of poor coordination of inhaler actuation with inspiration. We have studied a new breath-actuated inhaler ("Autohaler" 3M Riker) which is designed to ensure correct coordination automatically. This study involves 100 children (aged 3-10 years) and includes both normal children and asthmatic patients. None of these children have previous experience using any type of inhaler. Each child is taught to use the "Autohaler" containing a placebo only. A video film is employed in order to standardize the teaching technique. Once the child is able to operate the new inhaler correctly, he or she inspires through an "autohaler" unit specially modified so that the inspiratory flow rate and the volume of air inhaled is measured by a pneumotachograph in series with the inhaler. The time point, within the inspiratory cycle, at which the inhaler is triggered is also recorded. The majority of children older than 7 years were able to use the "Autohaler" after a few minutes instruction. Therefore, this is a valuable alternative in this age group. © 1990 Springer-Verlag New York Inc.