The effect of long-term inhaled steroid therapy on linear growth in asthmatic children is still a point of controversy. We tried to clarify the effect of long-term treatment with inhaled beclomethasone dipropionate (BDP) on linear growth and final height of asthmatic children. Height data measured annually from 12 years (beginning at age 10 years in most patients) to 20 years of age were retrospectively collected from clinical records in 97 moderate to severe asthmatics (49 boys, 48 girls) born in 1971-1975 who were observed regularly for more than 8 years at our outpatient clinic. Data were expressed as standard deviation scores and were compared between patients treated with BDP (30 boys and 31 girls, mean daily dosages were 300-800 microg) and without BDP. Growth delay in the early period of puberty and catch-up growth in the late period of puberty was found in both patients treated with and without BDP. The age of onset of treatment with BDP inhalation had no influence on linear growth, and asthmatic children receiving optimum treatment eventually attained standard final height for their age group. Long-term treatment with inhaled BDP in conventional doses does not significantly impair linear growth in asthmatic children.