Sleep quality can be significantly impacted by nasal congestion, a common symptom related to allergic rhinitis (AR). This may lead to decreased learning ability, productivity at work or school, and a reduced quality of life. A number of inflammatory cells and the release of inflammatory mediators lead to increased nasal congestion, causing disrupted sleep and subsequent daytime somnolence. Therefore, it is important to treat AR with medications that improve congestive symptoms without worsening sedation. Second-generation antihistamines and anticholinergic drugs are well tolerated but have little effect on congestion and therefore are limited in their ability to reduce AR-associated daytime somnolence. However, intranasal corticosteroids reduce congestion, improve sleep and sleep problems, and reduce daytime sleepiness, fatigue, and inflammation. Montelukast, a leukotriene receptor antagonist, has joined the approved therapies for AR. Montelukast significantly improves both daytime and nighttime symptoms. AR treatment should endeavor to improve daytime and nighttime symptoms, sleep, and productivity thereby improving quality of life.