Cognitive deficits and psychiatric manifestations such as depression and psychosis have been associated with obstructive sleep apnea (OSA) syndrome. We report a patient with OSA admitted to our center because of acute delirium of sudden onset at night, during sleep, and which impelled the patient to jump out of the window of his home. After exhaustive study, no other causes were found for the delirium, which resolved when nasal continuous positive airway pressure (nCPAP) was initiated. We believe that it is clinically important to be aware of this association, since it identifies a new, treatable cause of delirium.