Hypertension is a well-recognized risk factor for cardiovascular disease in adults. Furthermore, many studies have shown that there is tracking among longitudinal pediatric blood pressure determinations. An important unresolved goal in pediatric hypertension research is to define at what level of pediatric blood pressure is a child at increased risk for adult hypertension. When the grant was awarded in February 1991, there had been two NHLBI Task Forces in Blood Pressure Control in Children which had published reports in 1977 and 1987. One of the goals of each task force was to define appropriate percentiles for blood pressure in children. In the Second Task Force Report, results from nine large epidemiologic studies were combined into a data base with more than 70,000 readings from which blood pressure percentiles were derived as a function of age and sex. However, many research workers stated that height is more strongly related to blood pressure than age and have urged that Normative data for pediatric blood pressure be demarcated by height rather than age.