Previous research has shown that improvements in symptoms and lung function with short-term treatment with inhaled corticosteroids are impaired in smokers compared with nonsmokers with asthma.6-8 Similarly, Clearie et al5 found no improvement in airway responsiveness to methacholine or mannitol in smokers with asthma treated with inhaled corticosteroid alone. Although insensitivity to inhaled corticosteroids is likely to contribute to poor asthma control in smokers, there are a number of unresolved issues regarding this phenomenon. First, not all smokers with asthma show insensitivity to short-term corticosteroid therapy, possibly due to differences in airway inflammation or intensity of smoking. The relationship between the intensity of exposure to cigarette smoke, either on a daily basis or cumulatively, and the development of corticosteroid insensitivity is not clearly established. Most studies,6 including that of Clearie et al,5 reporting reduced responsiveness to corticosteroids have recruited patients with a smoking history >10 pack-years. Second, long-term treatment with inhaled corticosteroid in smokers may have beneficial effects, such as reducing rates of decline in lung function.9 Taken together, these findings suggest that despite the association between smoking and corticosteroid insensitivity, inhaled corticosteroids should continue to be prescribed to all smokers with asthma.