Respiratory control abnormalities may result in cor pulmonale. This report summarizes the clinical history, diagnostic evaluation, treatment, and outcome of 16 infants and children presenting with cor pulmonale subsequently found to be due to sleep-dependent hypoventilation. Eleven patients had cardiomegaly and electrocardiographic evidence of right ventricular hypertrophy (RVH) while 5 had only severe RVH or biventricular hypertrophy (BVH). Four infants with central hypoventilation syndrome (CHS)--absence of sleep-related ventilatory drive--had severe sleep-dependent asphyxia and resultant acute respiratory failure; all were ultimately treated with phrenic nerve pacing. One patient with alveolar hypoventilation syndrome (AHS)--a partial deficit in ventilatory drive during sleep--presented with severe pulmonary hypertension and ultimately died despite symptomatic relief with respiratory stimulants. Eleven patients presented with obstructive sleep apnea (OSA) and sleep-dependent asphyxia secondary to intermittent complete or to prolonged partial upper airway obstruction. Localized airway obstruction due to an anomalous innominate artery in 1 child was corrected by arteriopexy. Four children underwent adenotonsillectomy (T&A) with disappearance of symptoms in 1, clinical improvement in 2 and no clinical improvement in another. This unimproved patient and the 6 remaining OSA children improved dramatically after tracheostomy to bypass the sleep-dependent airway obstruction; none presently has evidence of cor pulmonale. In summary, early recognition and appropriate treatment of respiratory control disorders will improve sleep ventilation, eliminate asphyxia during sleep, and prevent the development of cor pulmonale.