Obstructive sleep-disordered breathing is common in children. From 3 percent to 12 percent of children snore, while obstructive sleep apnea syndrome affects 1 percent to 10 percent of children. The majority of these children have mild symptoms, and many outgrow the condition. Consequences of untreated obstructive sleep apnea include failure to thrive, enuresis, attention-deficit disorder, behavior problems, poor academic performance, and cardiopulmonary disease. The most common etiology of obstructive sleep apnea is adenotonsillar hypertrophy. Clinical diagnosis of obstructive sleep apnea is reliable; however, the gold standard evaluation is overnight polysomnography. Treatment includes the use of continuous positive airway pressure and weight loss in obese children. These alternatives are tolerated poorly in children and rarely are considered primary therapy. Adenotonsillectomy is curative in most patients. Children with craniofacial syndromes, neuromuscular diseases, medical comorbidities, or severe obstructive sleep apnea, and those younger than three years are at increased risk of developing postoperative complications and should be monitored overnight in the hospital.