The potential risks of antiasthmatic inhaled steroid therapy are essentially dose-related and include oropharyngeal complications such as thrush and dysphonia, and systemic complications such as hyperactivity, behavioural change, hypothalamic-pituitary-adrenal axis suppression, facial and weight changes characteristic of hypercortisonism, cataracts, increased intraocular pressure, dermal atrophy causing steroid purpura, retarded growth in children and osteoporosis. A few cases of fracture or acute adrenocortical insufficiency have been reported. Because concern about these potential risks is an important impediment to the use of inhaled steroids, practical measures aimed at minimizing these risks are discussed.