Objectives: The purpose of this study was to assess the effects of simvastatin therapy on the plaque regression and vascular remodeling at the peri-stent reference segments in normocholesterolemic patients using serial intravascular ultrasound (IVUS) observation. Methods: We retrospectively investigated poststenting and follow-up IVUS findings in 380 peri-stent (bare-metal stent) reference segments in 196 normocholesterolemic patients [simvastatin 20mg group (n=132) vs. non-simvastatin group (n=64)]; 182 lesions were located at proximal and 198 lesions were located at distal to the stent. Quantitative volumetric IVUS analysis was performed at 5-mm vessel segments immediately proximal and distal to the stent. Results: IVUS follow-up was performed at a mean of 9.4 months after stenting (range 5-19 months). By volumetric IVUS analysis, significant increase in mean P&M area, and significant decrease in mean lumen area and mean EEM area were observed at follow-up for both proximal and distal stent edges in both simvastatin and non-simvastatin group. However, there were no significant differences in changes of mean P&M area (proximal: simvastatin; +0.3짹0.2 mm2 vs. non-simvastatin; +0.7짹0.4 mm2, and distal: simvastatin; +0.4짹0.2 mm2 vs. non-simvastatin; +0.7짹0.3 mm2), mean lumen area (proximal: simvastatin -0.7짹0.4 mm2 vs. non-simvastatin -1.1짹0.6 mm2, and distal: simvastatin -0.7짹0.4 mm2 vs. non-simvastatin -1.0짹0.6 mm2) and mean EEM area (proximal: simvastatin; -0.4짹0.4 mm2 vs. non-simvastatin; -0.4짹0.3 mm2, and distal: simvastatin; -0.3짹0.3 mm2 vs. non-simvastatin; -0.3짹0.2 mm2) from poststenting to follow-up at both proximal and distal edges between simvastatin and non-simvastatin group. Conclusions: Usual dose of simvastatin does not inhibit plaque progression and lumen loss at the peri-stent reference segments in normocholesterolemic patients who underwent bare-metal stent implantation.