The prevalence of apneas is increased in the elderly. In the present paper, we briefly discuss the data on epidemiology, clinical significance, morbidity and mortality of sleep apnea in the elderly. We further try to identify possible mechanisms linking aging and sleep apnea that may explain the high prevalence found in aged patients. Structural changes in upper airway, increase in pharyngeal resistance, oscillations in upper airway resistance and sleep instability are among the main factors that may be involved. Last, we present data on 389 apneics consecutively diagnosed in our sleep laboratory, separated according to whether they were less or more than 65 years of age. In the group of elderly patients that cannot be extrapolated to a random sample of the general population, sleep apnea does not seem to be different in terms of severity of breathing disorders, sleep data and therapeutic implications. Further studies are needed to determine whether or not the associated morbidity is different in the elderly; these studies could lead to different diagnosis strategies and therapeutic approaches.