In a large group of young (n = 194) and elderly (n = 148) healthy subjects, we explored the relationship between ambulatory blood pressure (BP) levels, within-subject BP variability, and age in men and women. The questions asked were: Do elderly subjects display higher BP levels and variability compared to a young group? Are there gender differences in BP level and variability? Are these gender differences similar in the young and the elderly subjects? Do age or gender influence BP in a similar way during waking and during sleep? Subjects wore an ambulatory BP monitor (Accutracker II) for 24 h. Individual levels and variability (standard deviations) were calculated for periods when subjects were awake and during sleep. Systolic BP was higher in the elderly women than in the young group. In comparison to the young subjects, both elderly men and women had higher diastolic BP. BP variability while subjects were awake was higher in the elderly, in women in particular. The higher levels of BP variability found in the elderly women may indicate relatively higher risk for end-organ damage, such as silent cerebrovascular damage.