Epidemiological data indicate that obesity is a risk factor for asthma. These data are supported by observations in several murine models of obesity. Ob/ob, db/db, and Cpe(fat) mice each exhibit innate airway hyperresponsiveness, a characteristic feature of asthma. These mice also respond more vigorously to common asthma triggers, including ozone. Here we discuss the implications of these data with respect to several mechanisms proposed to explain the relationship between obesity and asthma: 1) common etiologies; 2) comorbidities; 3) mechanical factors; and 4) adipokines. We focus on the role of adipokines, especially TNF-alpha, IL-6, leptin, and adiponectin. Understanding the mechanistic basis for the relationship between obesity and asthma may lead to novel therapeutic strategies for treatment of the obese asthmatic subject.