Episodic apnea leading to asphyxia is a relatively common disorder of young children. Important apnea syndromes include apnea of prematurity, "narrow upper airway syndrome," congenital hypoventilation syndrome, breath-holding spells, and "near-miss" sudden infant death syndrome. More recently described syndromes include apnea associated with feedings, regurgitation or gastroesophageal reflux, and apnea initiated by epileptic seizures. Apnea occurring during wakefulness is common and may be related to that occurring during sleep. Knowledge of the clinical features and pathophysiology of these various kinds of apnea is important in their management.