It is well known that blood pressure (BP) levels persist over time. The present investigation examines tracking of elevated BP from childhood to adulthood and its progression to essential hypertension. In a community study of early natural history of arteriosclerosis and essential hypertension, a longitudinal cohort was constructed from two cross-sectional surveys > 15 years apart: 1505 individuals (56% female subjects, 35% black), aged 5 to 14 years at initial study. Persistence of BP was shown by significant correlations between childhood and adulthood levels (r = 0.36 to 0.50 for systolic BP and r = 0.20 to 0.42 for diastolic BP), varying by race, sex, and age. These correlations remained the same after controlling for body mass index (BMI). Twice the expected number of subjects (40% for systolic BP and 37% for diastolic BP), whose levels were in the highest quintile at childhood, remained there 15 years later. Furthermore, of the childhood characteristics, baseline BP level was most predictive of the follow-up level, followed by change in BMI. Subsequently, even at ages 20 to 31 years, prevalence of clinically diagnosed hypertension was much higher in subjects whose childhood BP was in the top quintile: 3.6 times (18% v 5%) as high in systolic BP and 2.6 times (15% v 5.8%) as high in diastolic BP, compared to subjects in every other quintile. Of the 116 subjects who developed hypertension, 48% and 41% had elevated childhood systolic and diastolic BP, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)