Different international guidelines recommend the early introduction of inhaled corticosteroids (ICS) and their regular use to gain clinical and functional control of persistent asthma. There is now evidence that the starting dose of all ICS is lower than previously regarded. Initial moderate ICS doses appear to be more effective than an initial low ICS dose. The lowest effective dose should always be seeked by a step-down procedure. More than 90% of benefit is achieved by approximately a daily regular dose of 200 microg of fluticasone or 400 microg of beclomethasone or budesonide. The beneficial effects of increasing the dose of ICS alone appear to be modest in most cases. Intermittent ICS therapy has been successfully used in the long term treatment of mild asthma. In general, twice-daily administration of ICS provides greater therapeutic benefit than a once-daily regimen in moderate asthma. When asthma control has been obtained, a once-daily regimen can be tried. In clinical practice, this has the potential advantage of increasing patients' compliance. Chlorofluorocarbon-free formulations of old ICS have also remarkably improved their clinical efficacy mainly through an increased peripheral deposition pattern. Despite some limitations due to poor response in neutrophilic asthma and to potential systemic side effects, ICS will certainly be the cornerstone of asthma therapy even the next future.