Inhaled corticosteroids have been the backbone of asthma therapy for the past 20 plus years. Although they have, for the most part, been effective in controlling asthma symptoms and preventing exacerbations, not all patients are universally responsive to their beneficial effects. In addition, several recent studies have failed to demonstrate a disease-modifying effect of inhaled corticosteroids, with clinically indicated doses failing to prevent long term deterioration in lung function and potential airway "remodeling". Furthermore, it is apparent that possible side effects are still a concern with currently available formulations. Steroid characteristics, which might improve the therapeutic index of this class of medicine by enhancing efficacy while minimizing side effects, are explored, with special emphasis on the molecule, ciclesonide.