The links between asthma and rhinitis are well documented and are based upon epidemiological, immunological and clinical observations. Leukotriene receptor antagonists (e.g. montelukast) are an established, effective and well tolerated treatment option for asthma, and more recent evidence now demonstrates their clinical utility in the treatment of allergic rhinitis. In seasonal allergic rhinitis, montelukast monotherapy has been shown to provide relief from daytime nasal symptoms (including congestion, runny nose, nasal itching and sneezing), as well as nighttime and eye symptoms. These clinical benefits were associated with reduced eosinophil counts in the blood, suggesting an effect on the underlying mechanisms of allergic inflammation. In addition, studies that have evaluated the combination of an antileukotriene with an antihistamine have typically shown a numerical and sometimes statistical benefit of combination therapy. Given the frequent coexistence and shared pathophysiologies of asthma and allergic rhinitis, a common therapeutic approach would seem warranted. Leukotriene receptor antagonists, such as montelukast, are emerging as a rational approach to ‘one airway’ disease management.