Inhaled corticosteroids are effective and safe treatments for childhood asthma in standard doses, yet at high dosages they may be associated with adverse events and suboptimal outcomes; add-on therapy is, therefore, recommended to minimise their use. We quantified prescribing of high-dose inhaled corticosteroids and add-on therapy in children in July 2003 and found that high-dose inhaled corticosteroids were prescribed to 10% of children aged 5-11 years and 6% of under-5's who were treated for asthma. Add-on therapy was lacking for almost half of these individuals. Some children were receiving treatment not in accord with current licences and evidence-based recommendations and, as such, may be at risk of adverse outcomes.