Background/Aims: Asthmatic children on long-term treatment with inhaled corticosteroids (ICS) may exhibit mild adrenal suppression. We aimed to test the hypothesis that baseline adrenal function of some asthmatic children might be lower than that of others and that this difference might be accentuated by ICS therapy. Methods: A low-dose Synacthen test was performed in 41 prepubertal asthmatic children placed on long-term inhaled budesonide (400 µg/day) prior to the onset of ICS treatment, 6 and 12 months later. Five children withdrew before the 6- and another 2 before the 12-month follow-up. Results: Low adrenal function was demonstrated in 4 children (9.8%) upon recruitment and in another 8 at the 6-month evaluation (22.2%). Adrenal function normalized in the aforementioned 4 children at the 6-month evaluation, while 6 (17.6%) exhibited suppressed adrenal function at the 12-month evaluation. Three of these patients had also exhibited adrenal suppression at the 6-month visit. A significant improvement in peak cortisol values from baseline to the 6- and 12-month evaluation (95% confidence intervals: –283.9 to –69.0 and –239.8 to –50.8, respectively) was evident when children with suppressed adrenal response at the second or third evaluation were excluded. Conclusions: In many asthmatic children, adrenal response improves on long-term ICS. The expected adrenal suppression of certain patients on maintenance ICS appears to constitute a separate phenomenon.