The National Asthma Council of Australia suggests that "the aim of preventive therapy should be to enable patients to enjoy a normal life (comparable with that of non-asthmatic children), with the least amount of medication and at minimal risk of adverse events. The level of maintenance therapy should be determined by symptom control and lung function in the interval periods." The British Thoracic Society/Scottish Intercollegiate Guidelines Network states that the aims of the pharmacological treatment of asthma should be to control symptoms, prevent exacerbations and achieve the best possible lung function with minimal adverse effects. We have used the current published international guidelines to highlight the international differences in management recommendations, and compared the possible pharmacological options with a focus on the above ideals. Cromones have been used for many years in childhood asthma. Most evidence suggests they now have little role. Regarding inhaled corticosteroids (ICS), beclomethasone and budesonide are essentially similar in their efficacy. Fluticasone propionate is equally as effective at one-half the equivalent dose of budesonide or beclomethasone. Adverse effects are rare in dosages <400 microg/day of budesonide and beclomethasone or <200 microg/day of fluticasone propionate, but may occur in individual patients. Relevant clinical adverse effects are rare and pharmacological systemic effects are less noticeable with budesonide and fluticasone propionate than with beclomethasone, but data are conflicting. Long-acting beta2-adrenoceptor agonists (beta2-agonists) are recommended once low-dose ICS have failed to control symptoms. The main pharmacological difference between the agents is that formoterol is a full beta2-adrenergic agonist, whereas salmeterol is a partial agonist at the beta2-adrenoceptor and has a unique pharmacological action. The main clinical distinction between these two agents is that their onset of bronchodilation differs. Bronchodilation begins at about 3 minutes after inhalation of formoterol, which is similar to the short-acting agents, whereas salmeterol has a much slower onset of action at about 15-30 minutes. The many in vitro differences between the two drugs are probably not clinically relevant. There are no comparative pediatric data on the leukotriene modifiers to make clear recommendations.