Asthma is an inflammatory disease of the lower respiratory tract, manifesting as intermittent constriction of the bronchial airways. Obstructive sleep apnea (OSA), on the other hand, is a state-dependent condition that is characterized by intermittent obstruction of the upper airway during sleep. Asthma symptoms are often worse at night. Many possible explanations have been put forth for the nocturnal deterioration of asthma symptoms, including alterations in the autonomic tone, changes in hormonal secretion, circadian changes in inflammatory cells and cytokines, and the possible role of acid reflux in the worsening of asthmatic symptoms at night. A relationship between asthma and OSA was noted > 25 years ago. Hudgel and Shucard1 described severe hypoxemia in coexistent asthma and OSA. Catterall et al2 noticed more hypoxemic episodes, especially during rapid eye movement sleep, in a group of 10 asthmatic patients compared to control subjects. Interestingly, they noticed the appearance of apneas and hypopneas but commented that these asthmatic patients did not have “classical sleep apnea syndrome.” In a later study, Fitzpatrick et al3 noted that 11% of asthmatic patients reported frequent snoring (ie, ≥ 4 nights a week) and frequently reported falling asleep while driving or operating machinery. In another questionnaire study4 of 2,202 subjects (267 asthmatic subjects), the presence of asthma was a stronger predictor of self-reported apneas than the other common risk factors like male sex, body mass index, and age. Despite these earlier observations, there has been a paucity of literature addressing comorbid OSA in asthmatic patients until recently.