The growth-inhibiting effect of exogenous corticosteroids has been reported in many papers. Most of them have concerned the clinical problems of asthma and rheumatoid arthritis but it is probable that the underlying disease is relatively unimportant in determining the effect on growth. Steroid therapy on alternate days seems to produce less undesirable effects than steroid treatment every day and corticotrophin may be preferable. Although the mechanisms are uncertain it seems likely that the action is peripheral and certainly exogenous growth hormone does not prevent the steroid effect. A minimal dosage of corticosteroids should always be used in replacement therapy for hypopituitarism.