Antihypertensive medications are used extensively in children despite a paucity of randomized, placebo-controlled trials. This study was among the first randomized, controlled pediatric antihypertensive medication trials, in which the combination drug bisoprolol fumarate/hydrochlorothiazide (B/HT) was compared with placebo. The study comprised a 2-week single-blind placebo screening period, a 6-week double-blind dose titration period, a 4-week double-blind dose maintenance period, and a 2-week double-blind dose-tapering period. One hundred and forty subjects were enrolled to achieve 94 randomized subjects treated either with B/HT ( n=62) or placebo ( n=32). B/HT induced significant reductions compared with placebo for average sitting systolic blood pressure (SiSBP) (9.3 vs. 4.9 mmHg, P<0.05) and sitting diastolic blood pressure (SiDBP) (7.2 vs. 2.7 mmHg, P<0.05). The placebo-subtracted BP reductions were greater in younger children and those with more-severe baseline hypertension. The percentage of subjects with BP less than the 90th percentile at study completion was 45% for B/HT and 34% for placebo ( P=NS). Although the study demonstrated that B/HT reduced BP safely compared with placebo, the large placebo effect and failure of most subjects to achieve target BP control make it uncertain whether B/HT is appropriate first-line therapy for pediatric hypertension, particularly in adolescents with mild-to-moderate BP elevation.