The OLmesartan on the progression of coronary atherosclerosis: evaluation by IntraVascular UltraSound (OLIVUS) trial demonstrated that an angiotensin II receptor blocker, olmesartan, reduces the rate of coronary atheroma progression as evaluated by intravascular ultrasound in patients with stable angina pectoris undergoing percutaneous coronary intervention. This substudy examined the impact of olmesartan on serum biomarkers and the relationship between biomarker changes and atheroma progression. Patients in the OLIVUS trial (n = 247) were randomly assigned to a control group or the olmesartan group. A subgroup of these patients (n = 135, 55 %) was analyzed at baseline and at 14 months. Patients' characteristics and blood-pressure control were identical between the control group (n = 65) and the olmesartan group (n = 70), and also between the subpopulation and total population. The change in the level of high-sensitivity C-reactive protein (hs-CRP) (mg/l) and adiponectin (μg/ml) was significantly greater in the olmesartan group than in the control group (between-group differences: 0.5 and -0.7; 95 % confidence interval: 0.2-0.8 and -1.3 to -0.1; P = 0.001 and 0.02, respectively). Multiple regression analysis revealed that the nominal changes in total atheroma volume and percent atheroma volume were significantly associated with the nominal change in hs-CRP in the olmesartan group but not in the control group. Olmesartan reduced hs-CRP in patients with stable angina, and this correlated with the change in coronary atheroma.