In adults, influence of body position on the occurrence of respiratory events during sleep is recognized, and increased numbers of respiratory events occur when the supine position is assumed.(1-4) In 1985, Orr et al. showed that body position did not influence respiratory events during sleep in children.(5) Recently, Fernandes do Prado et al. showed that children had a lower obstructive apnea hypopnea index (AHI) in supine position.(6) Results of these two studies are different from others performed on adults. Moreover, upper airway abnormalities were not considered in these studies.