Three children presented with adrenal crises, manifested by vomiting and hypoglycaemia, after protracted courses of high-dose inhaled corticosteroids for asthma. Significant dose reduction was possible in all three without loss of asthma control, emphasising the importance of back-titration to minimise dose. Parents of children taking high doses of inhaled corticosteroids should be alerted to the clinical features of adrenal insufficiency. If suspected, prompt medical assessment should be arranged, including serum glucose and cortisol measurement.