Both obesity and sleep apnea are prevalent health conditions that frequently coaggregate. Obesity-associated inflammation may influence asthma control; the relation of sleep apnea to asthma or allergic rhinitis may be bidirectional. Both obesity and sleep apnea are associated with augmented levels of inflammation and oxidative stress, and it is biologically plausible that the proinflammatory effects of one disorder influence the expression of the other disorder. This article elucidates mechanistic associations among obesity, sleep apnea, and systemic inflammation; highlights interrelationships between these factors with cardiopulmonary disease; and identifies specific areas for future research directions.