Few data are available on the association between body mass index (BMI) and blood pressure in elderly individuals, particularly among minority groups. We studied the cross-sectional association of BMI with systolic and diastolic pressures in 1378 Japanese American men 60 to 82 years of age who were participants in the population-based Third Lipoprotein Examination of the Honolulu Heart Program conducted between 1980 and 1982. When the subjects were divided into 5-year age groups, mean BMI decreased linearly with increasing age. Mean systolic pressure rose from 134.8 mm Hg in the first quintile of BMI to 138 in the second and 141.8 in the third quintiles, with levels of 139.2 and 142 in the fourth and fifth quintiles, respectively (test for trend, P = .083). Mean diastolic pressure rose from 78.1 mm Hg in the lowest quintile of BMI to 83.9 in the highest (test for trend, P = .008). We performed multiple regression analysis, controlling for factors known to influence blood pressure values, including age, physical activity index, alcohol intake, current smoking status, and diabetes mellitus. The association between BMI and both systolic and diastolic pressures remained highly statistically significant in these analyses. These results show that obesity and high blood pressure continue to be highly correlated even in old age and suggest that it may be possible to modify rates of hypertension by changes in body weight.