This study was performed to evaluate the safety and efficacy of additional antihypertensive therapy with angiotensin II type 1 receptor blocker (ARB; olmesartan or valsartan) after successful stent implantation in patients with coronary artery disease (CAD). Fifty patients with CAD after successful stent implantation were included in this study. They were divided into an ARB group, which initially received olmesartan (n=20, 14+/-8 mg day(-1)) or valsartan (n=20, 60+/-23 mg day(-1)) immediately after stent implantation, and a non-ARB group (n=10) according to their blood pressure (BP). Follow-up coronary angiography, measurement of BP and blood sampling were performed before (at baseline) and 6-8 months after stent implantation (at follow-up). There were no significant differences in the baseline characteristics between the groups, except for BP. Although there were no changes in % diameter restenosis between the groups, the BP level in the ARB group at follow-up showed a significant reduction (125+/-12/69+/-9 mm Hg) and reached the target BP. There were no critical adverse effects in the ARB group throughout the study period. In addition, serum high-sensitive C-reactive protein (hs-CRP) and pentraxin 3 were significantly decreased in the ARB group but not in the non-ARB group. Although olmesartan and valsartan induced similar BP-lowering effects, olmesartan but not valsartan induced a significant decrease in hs-CRP, but did not increase serum uric acid. In conclusion, antihypertensive therapy with add-on low-dose ARB after stent implantation was safe and achieved the target BP. In particular, olmesartan had an anti-inflammatory effect.