We investigated the prevalence of sleep-disordered breathing (SDB) in healthy 80 year-old subjects (n = 38) as compared with healthy 70-(n = 33) and 60-year-old subjects (n = 34). The apnea-hypopnea index (AHI) increased significantly across decades: 39.5% (15 of 38) of 80 year olds, 33.3% (11 of 33) of 70 year olds, and 2.9% (1 of 34) of 60 year olds had an AHI greater than or equal to 5 (chi 2 = 14.0, p less than 0.001). The prevalence of SDB as measured by a more stringent apnea index criterion of greater than or equal to 5 was 18.9% of those in their 80s, 12.1% in their 70s, and 0% in their 60s (chi 2 = 6.63, p less than 0.05). Significant gender differences were noted in the proportion of subjects with AHI greater than or equal to 10: 22.4% of men versus 5.4% of women (chi 2 = 4.25, p less than 0.05). These data suggest that SDB increases with advancing age even in the healthy elderly and may be more marked in healthy men than women.