Rhinosinusitis and asthma are common conditions associated with significant morbidity and health care costs. Recent studies in adults have suggested that rhinosinusitis and asthma may be manifestations of an inflammatory process within a continuous airway rather than fully separate diseases that only act locally; and, in fact, the presence of upper airway disease may influence lower airway disease. Controlling upper airway infection, inflammation, and symptoms may improve signs and symptoms of asthma. Pediatric studies regarding this matter are few, but the impact of rhinosinusitis and asthma is still immense and significant in children. This article discusses several pediatric studies regarding medical or surgical management of sinusitis and asthma outcome. These studies show that aggressive treatment of sinusitis when present can significantly improve asthma symptoms and quality of life in children, indicating that sinusitis may play an important role in initiating or exacerbating asthma. These findings have important implications for the physician treating a child with chronic asthma.