Since the report from the national high blood pressure (BP) education program working group on BP in children and adolescents and the introduction of a new description called prehypertension many data have been provided on its rate of progression to hypertension, its prevalence and association with other cardiovascular (CV) risk factors and its therapy. Making a diagnosis of prehypertension in a child or adolescent identifies an individual at increased risk for early-onset CV disease who requires specific treatment. Thus, routine BP measurement is highly recommended at every health-care encounter beginning at 3 years of age. This review will present updated data on prehypertension in children and adolescents to increase awareness of health-care providers to the seriousness of this condition. Optimal BP measurement techniques as well as the evaluation and management of prehypertension will be discussed and preventive strategies to reduce the CV risk will be presented.