According to current guidelines, inhaled corticosteroids (ICS) are the preferred primary long-term treatment for asthmatic children of all age groups, but leukotriene receptor antagonists can be considered to be an alternative treatment for mild persistent asthma. In this article, all randomized double-blind efficacy studies comparing the long-term (>4-week) treatment using a leukotriene receptor antagonist with an inhaled corticosteroid in asthmatic children were critically reviewed. In school-aged children, five reports with an adequate study design were available. All of these studies compared montelukast with inhaled fluticasone. The meta-analysis of the two main outcome measures, forced expiratory volume in 1 s (weighted mean difference, 4.6% predicted, 95% confidence interval: 3.5-5.5) and asthma control days (respectively, 5.6%, 4.3-6.9) demonstrated the superiority of fluticasone over montelukast. Many other clinical and pulmonary outcomes also consistently showed that low-dose inhaled fluticasone was more effective than montelukast in the long-term management of mild to moderate persistent asthma. A more favorable response to fluticasone over montelukast was associated with more severe disease or markers of allergic inflammation. About a quarter of patients benefited more from montelukast than fluticasone. In children under school age, no comparative studies were available. However, long-term montelukast treatment was found to be effective in placebo-controlled studies in asthmatic children aged >2 years. These findings support the present international recommendations for ICS as the preferred first-line controller therapy for mild to moderate persistent childhood asthma. If montelukast is selected as a monotherapy and asthma is not adequately controlled within 4-6 weeks, the treatment should be discontinued and the preferred medication initiated.