BACKGROUND The risk of suppression of hypothalamic-pituitary-adrenal (HPA) function in children on topical glucocorticosteroids is currently much debated. OBJECTIVE To review data on HPA function in children with asthma and rhinitis on topical glucocorticosteroids, and to discuss the value of HPA function measures in clinical practice and research. METHOD A review of peer refereed data. RESULTS/CONCLUSIONS There is no evidence that insufflated or inhaled glucocorticosteroids in recommended doses have ever caused clinically significant HPA insufficiency in any child. Using sensitive measures of basal adrenal activity, however, several studies have found suppressive effects with specific drugs, high doses and application systems. These observations may represent homeostatic diminution in endogenous cortisol. Such measures have no place in the management of children on topical glucocorticosteroids, but may be useful in clinical trials assessing systemic activity of administration regimens and application devices. In children growth suppression seems to the most important adverse effect of topical glucocorticosteroids.