We describe a syndrome characterized by acquired micrognathia, hypersomnia, and periodic apneas during sleep. Six patients affected with the syndrome underwent nocturnal and diurnal polygraphic recordings that demonstrated that during sleep there is an uninterrupted succession of apneas, primarily the obstructive type, analogous to those observed in Pickwickian syndrome. Simultaneous recording of pulmonary and systemic arterial pressure during sleep and repeated blood gas analyses have shown that as soon as the apneas appear there is a decisive increase in pulmonary and systemic pressure and serious alveolar hypoventilation. The hemodynamic and ventilatory changes are even more intense during rapid eye movement sleep. Tracheostomy, performed on five of our patients, is the only treatment producing complete clinical remission of the syndrome.