Obesity is one of the major health challenges of recent time. The prevalence of obesity has increased dramatically worldwide during the last two decades and is only believed to increase over coming years. It is well known that overweight and obesity increases risk for a number of adverse health effects, including diabetes, cardiovascular diseases, and multiple cancer types that in turn increases the risk of associated morbidity and mortality. Of late, it has also been shown that obesity increases susceptibility to bacterial and viral infections and infectious agents also have a role in the pathogenesis of obesity. Intriguingly, less recognized is the fact that respiratory disorders, such as obstructive sleep apnea, pulmonary embolism, chronic bronchitis, and asthma are also associated with obesity. The ensuing paragraphs discuss the complex relationship between obesity and the respiratory systems, and the risk and outcome of infections in obese adults with particular focus on respiratory infections.