The generally accepted polysomnographic criteria for diagnosis of sleep apnea is exceeded by elderly subjects with such frequency that the validity of its application to this age group has been questioned. We studied a group of elderly volunteers with nocturnal polysomnography and partitioned them into 2 groups based upon an apnea index of greater than or less than 5 per hour. The results of a protocol evaluating the presence of potential complications of sleep apnea including cardiac arrhythmias, systemic hypertension, cor pulmonale, daytime sleepiness, and cognitive impairment were compared for the 2 groups. No excess incidence of cardiovascular complications was found. Although an increase in daytime sleep tendency was shown for the group with more frequent apneas, no appreciable deficits in cognitive performance were demonstrated. Although apnea during sleep in the elderly may be associated with an increase in daytime sleepiness, it may not necessarily result in other physiologic or neuropsychologic consequences. Therapeutic intervention for these abnormalities should be carefully considered prior to the institution of treatment in light of these observations.