In the 2004 report from the National High Blood Pressure (BP) Education Program Working Group on BP in Children and Adolescents, the term "high normal BP" was replaced with the designation "prehypertension". It was proposed that BP levels that were higher than normal but did not reach the level of hypertension posed an increased risk for progression to hypertension. The overall intent of this description was to help identify children who were at the greatest risk for the development of hypertension. These are children and adolescents for whom targeted prevention programs are expected to be most beneficial. Following the 2004 report, the prehypertension condition has been examined and described in adolescents as well as adults. This review summarizes the knowledge that has been gained on prehypertension including clinical characteristics, rates of progression to hypertension, and evidence of cardiovascular pathology.