Each child will complete a 1- to 4-week Screening Period where they will stop taking their current blood pressure lowering drug(s), a 4-week Treatment Period where they will receive placebo or one of the ramipril doses, and a Follow-up visit 1 week after completion of the Treatment Period. Children diagnosed with hypertension according to the fourth report on the diagnosis, evaluation and treatment of high blood pressure in children and adolescents (U.S. report), will be included in the study if their blood pressure meets certain values.