This study is a prospective multicenter study designed to investigate the effects of lipid-lowering therapy with pitavastatin on atherosclerotic plaque in patients with coronary heart disease, and to determine which factor is more closely associated with plaque regression. Participants (n = 63) were treated with pitavastatin for 12 months, and the carotid intima–media thickness (IMT) was measured by ultrasound before and after treatment. Mean IMT slightly but significantly decreased (from 0.99 ± 0.33 to 0.94 ± 0.28 mm for overall, P = 0.01) regardless of the presence of pretreatment with other statins. There were no significant relations with hs-CRP, malondialdehyde-LDL, LDL cholesterol, and smaller LDL cholesterol levels despite their decrease by pitavastatin. Decreases in mean IMT were observed significantly more frequently in subjects with high on-treatment HDL cholesterol levels than with low HDL cholesterol levels (P = 0.017). The change in mean IMT tended to be inversely correlated with increments in HDL cholesterol and apolipoprotein A-I. The IMT regression was more often observed in the absence of diabetes and metabolic syndrome. In conclusion, we demonstrated that treatment with pitavastatin attenuated atherosclerotic plaque. This effect was associated with the level of HDL cholesterol, and was stronger in the absence of diabetes and metabolic syndrome in our ischemic heart disease patients.