Blood pressures (BP) were determined in 1409 boys aged 8-16 years at three one-year intervals in New York City (NYC) and in Greece, areas of high and low incidence of coronary heart disease (CHD), respectively. Non-Greek American boys had significantly lower systolic and diastolic BP than all the Greek boys from NYC and from Greece. The boys residing in Crete and in Athens had higher BP than all other cohorts. After covariance adjustment for height, ponderal index and age, significant differences among the cohorts showed the non-Greek American cohort to have the lowest and the Cretan cohorts the highest BP levels. The Cretans lead a lifestyle noted for the absence of other risk factors for CHD. Thus, while the incremental increase in blood pressure might have a corresponding increase in CHD risk among individuals, there are fewer individuals in Crete at elevated risk overall based on the CHD experience of the U.S. and Greece.