Blood pressures were recorded in 319 ambulatory subjects, largely men, age 50 to 99 years. The mean systolic pressures were maximal in the seventh and eighth decades (136.0 and 132.1 mm Hg with the subjects supine and erect, respectively), whereas the mean diastolic pressures fell progressively after age 69. The distribution of postural changes in mean blood pressure was similar in each decade; a decrease of 20 mm Hg on more was noted in 3.4% of the subjects aged 80 to 99 years and in 4.1% of those aged 50 to 79 years. The frequency of postural hypotension was 4.6% in subjects treated with diuretics and 3.4% in those not so treated. Blood pressures and the frequency of postural hypotension did not progressively increase in age in this elderly population.