Inhaled corticosteroids are established as the mainstay of maintenance therapy for chronic asthma. However, there remains some debate regarding the safety of long-term use of these agents, particularly in children. This concern mainly stems from the findings of short-term studies assessing the effects of inhaled corticosteroids on lower leg growth rate or the hypothalamic-pituitary-adrenal axis. However, the clinical relevance of these findings to long-term treatment is unknown and significant uncertainty exists regarding the predictive value of changes in cortisol levels and clinically relevant changes in growth or bone mineral density. To assess the safety of long-term use of inhaled corticosteroids in children with asthma, a systematic review of the literature was performed focusing on randomised, controlled studies of >or=12 months' duration, to obtain data with maximum relevance to clinical practice. Specific searches were conducted to identify studies examining each of the following three areas: growth, bone mineral density and cortisol levels. Fourteen studies met the inclusion criteria for statural growth, four for bone mineral density, and ten for cortisol levels. There was some evidence of a small decrease in statural growth during the initial period of inhaled corticosteroid therapy. This effect was more marked at daily doses of >200 microg and did not apply to all treatment regimens. Studies examining final attained adult height found no difference between patients treated with inhaled corticosteroids and those receiving nonsteroidal therapy. None of the studies investigating effects on bone mineral density found any adverse effects of inhaled corticosteroid therapy. Finally, recommended doses of inhaled corticosteroids generally had little or no effect on plasma- or urinary-cortisol levels versus nonsteroidal therapy. In conclusion, this literature review supports the theory that recommended doses of inhaled corticosteroids can be administered to children for the long-term management of asthma with minimal risk of clinically relevant adverse effects on growth, bone density or cortisol levels.