BACKGROUND AND OBJECTIVES: The beneficial effects of statins in preventing cardiovascular events may depend, in part, on their anti-inflammatory action. We previously reported that low dose statin therapy has cholesterol lowering effects, but no effect on inflammation, and proposed that a sufficient dose of therapy might be needed to achieve anti-inflammatory action. The aims of this study were to confirm the suggestions made in our previous study. SUBJECTS AND METHODS: Fifteen unstable angina patients who were enrolled in our previous study were evaluated. The usual dose (20 mg) of simvastatin was administrated for 26 weeks, blood samples collected following the administration and tested for their lipid profiles and inflammatory markers (IL-6, CRP). The changes in the lipid profiles and inflammatory markers, from baseline levels, to the usual and low doses of statin therapy were evaluated. RESULTS: The changes in the IL-6 and hsCRP levels after the usual dose simvastatin therapy compared with the baseline levels were -72.8 and -59.6% (p< 0.05), respectively. The changes in the IL-6 and hsCRP levels after the usual dose simvastatin therapy compared with a 5 mg dose were -77.2 and -47.1% (p< 0.05), respectively. There was statistically significant correlation between the change in the levels of IL-6 and hsCRP during statin therapy. CONCLUSION: Our data confirmed the preliminary result of Chung et al, which suggested the usual dose of simvastatin is required to inhibit the inflammation of unstable plaque in patients with unstable angina associated with hypercholesterolemia.