Partial airway obstruction due to the enlargement of the tonsils and adenoids is a well recognized clinical entity, but cardiorespiratory changes due to chronic obstruction have infrequently been reported. Four children with severe nasopharyngeal obstruction due to tonsil and adenoid hypertrophy, who developed pulmonary hypertension and cardiac failure, were studied. Relief of upper airway obstruction by adenotonsillectomy resulted in a regression of the presenting signs and symptoms.