Among several beneficial cardiovascular actions of statins, experimental studies have suggested that statins may also induce a mild blood pressure (BP) reduction. However, clinical data were controversial and the potential hypotensive statin effect remains uncertain. This study aimed to investigate the effect of atorvastatin on ambulatory BP in patients with mild hypertension and hypercholesterolaemia. A total of 50 patients with mild hypertension and hypercholesterolaemia participated in this double-blind, randomized, placebo-controlled study. Patients were randomized to either 10 mg atorvastatin or placebo for 26 weeks. Background antihypertensive treatment, if any, remained unchanged during follow-up. At baseline and study-end (26 weeks), ambulatory BP monitoring and blood sampling for determination of standard biochemical and safety parameters were performed in all participants. BP loads were defined as the percentage of BP measurements exceeding the hypertension threshold of 140/90 mm Hg for daytime and 125/75 mm Hg nighttime period. Atorvastatin significantly reduced 24-h systolic and diastolic BP (DBP; median (range)) as compared with placebo (-5.0 (-21.0, 4.0) vs +1.0 (-6.0, 7.0) mm Hg, P<0.001 and -3.0 (-16.0, 2.0) vs +0.1 (-7, 4) mm Hg, P<0.01, respectively). Reductions in systolic and DBP loads during follow-up were also evident in the atorvastatin, but not in the placebo group. BP-lowering effects of atorvastatin were consistent in both daytime and nighttime periods. This study shows a mild, but consistent throughout the 24-h period BP-lowering effect of atorvastatin in patients with mild hypertension and hypercholesterolaemia. This beneficial effect of atorvastatin on BP may represent another pathway through which this drug class provides cardiovascular risk reduction.