Objective: The increase of high density lipoprotein cholesterol(HDL-C) decreases cardiovascular events. Statin therapy increased HDL-cholesterol level by 5-10% in clinical trials. But in some patients, HDL-cholesterol level decreased with statin therapy. This study was designed to evaluate the effect of pitavastatin on HDL-C level and its postulated mechanism in patients with metabolic syndrome. Methods: This study was a mono-arm study with pitavastatin 2mg designed to investigate the effect of pitavastatin on HDL-C level, other lipoprotein profiles and whether its effect on HDL-C level was associated with cholesterol ester transfer protein (CETP) or not. The patients who had metabolic syndrome were enrolled and treated with the treatment guideline of Korean Society of Lipid and Atherosclerosis. After washout period of 4 weeks with therapeutic lifestyle change, the patients were received pitavastatin 2mg for 8 weeks. The primary objective was the change of HDL-C level after statin treatment for 8 weeks. Secondary objectives were the changes of low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglyceride levels, apolipoprotein (apo) B/A1 ratio, high sensitivity C-reactive protein level (hsCRP) and CETP. Results: 66 patients were screened and 63 patients (mean 59.4 years of age, male 38.9%, BMI 28.1 kg/m2) were treated with pitavastatin. After 8 weeks' treatment, HDL-C level increased 5.4% from 41.5짹6.6 mg/dL to 43.5짹8.4 mg/dL (p=0.037). Pitavastatin treatment significantly decreased LDL-C by 38.8%, total cholesterol by 26.1%, triglyceride by 13.1%, apoB/A1 ratio by 42%. hsCRP level showed the tendency of decrease but this change did not reach statistical significance. CETP decreased 26.3% with pitavastatin treatment, but was not associated with HDL-C increase. The predictive factors of HDL-C increase with pitavastatin therapy were male, absence of diabetes, BMI less than 30 kg/m2, old age. Conclusion: Pitavastatin treatment significantly increased HDL-C level and decreased total cholesterol, LDL-C, triglyceride levels and apoB/A1 ratio in patients with metabolic syndrome. CETP change was not associated with HDL-C increase in this study.