Inhaled corticosteroid has been shown to be effective in the management of asthma. However, there is a lack of studies that assess the effect of cessation after long-term treatment with inhaled corticosteroid. This question was addressed in 28 children with stable asthma, aged 11 to 18 yr of age, who had completed 28 to 36 months of treatment with inhaled corticosteroid (budesonide 200 micrograms 3 times/day) and inhaled beta-2-agonist (salbutamol 200 micrograms 3 times/day). The children were randomized in a 1:2 ratio in a double-blind study either to continue budesonide (n = 8) during a period of 6 months or to decrease the dose of budesonide (n = 20) within 2 months, followed by placebo for 4 months. Treatment with salbutamol 600 micrograms daily was continued in both groups. Eight children from the tapering-off group withdrew, mainly due to symptoms of asthma, compared with none in the continuous treatment group. Five patients in the tapering-off group experienced exacerbations for which prednisolone was given, compared with none in the continuous treatment group. After tapering-off, symptoms of asthma and additional bronchodilator use increased, and both FEV1% predicted and PD20 histamine (provocation dose of histamine causing a 20% fall in FEV1) decreased, whereas these all remained unchanged in the group that continued treatment with inhaled corticosteroid. We conclude that in this study long-term treatment with 600 micrograms budesonide daily suppressed underlying mechanisms of asthma, but did not cure the disease.