Abstract--Offspring of hypertensive parents are at high risk of future hypertension and subsequent cardiovascular diseases. We investigated whether early treatment with an angiotensin-receptor blocker in young normotensive offspring of hypertensive parents persistently lowered blood pressure after treatment withdrawal, a possibility supported by animal studies. The study is an investigator-initiated, double-blind study of 110 healthy normotensive subjects aged 18 to 36 years where both parents have essential hypertension randomly assigned to 1 of 2 treatment groups: candesartan (Atacand, Astra Zeneca), 16 mg o.d. or placebo. The intervention period was 12 months, with 24 months of follow-up. Primary outcome was mean 24-hour ambulatory blood pressure recordings (mean AMBP) after 12 and 24 months follow-up and was based on intention to treat (n=110). Secondary outcomes were changes during treatment in mean AMBP, left ventricular mass, renal hemodynamics, and adverse events during intervention and were based on those completing the intervention period (n=105). Primary outcome: At 12 and 24 months follow-up, mean AMBP was not different to placebo. Secondary outcomes: After 12 months of intervention, mean AMBP was reduced: -3.9/-3.4 mm Hg for candesartan versus 0.3/0.6 mm Hg for placebo, P<0.0001. Renal vascular resistance and left ventricular mass were also reduced (P=0.0007, P=0.019, respectively). There were no significant differences in adverse advents between the 2 groups. In conclusion, temporary treatment of subjects at high familial risk of future hypertension with an angiotensin receptor blocker is feasible, but the treatment had no persistent effect on blood pressure when treatment was withdrawn.