Although the clinical benefit of statins have been demonstrated in both genders, gender differences in the response to statin therapy on plaque morphologic changes have not been reported. A total of 66 nonculprit plaques from 46 patients who had serial image acquisition at baseline, 6 months, and 12 months by both optical coherence tomography and intravascular ultrasound (IVUS) were included. Patients were treated with atorvastatin 60 mg (AT60) or 20 mg (AT20). The baseline characteristics were similar between women (n = 16) and men (n = 30) except for age (59.3 ± 6.8 vs 52.5 ± 10.6 years, p = 0.027) and smoking status (12.5% vs 70.0%, p <0.001). The change in fibrous cap thickness (FCT) at 12 months was significant in both groups (108.8 ± 87.4 μm, p <0.001, 91.3 ± 70.1 μm, p <0.001, respectively) without significant difference between the groups (p = 0.437). The percent change in mean lipid arc at 6 months was significantly greater in women than that in men (−12.8 ± 18.8% vs −1.56 ± 21.8%, p = 0.040). In women, the percent change of FCT in the AT20 group was similar to that in the AT60 group (182.5 ± 199.5% vs 192.9 ± 149.7%, p = 0.886). However, in men, the percent change of FCT in the AT20 group was significantly smaller than that in the AT60 group (92.2 ± 90.5% vs 225.9 ± 104.3%, p <0.001). No significant change in percent atheroma volume by IVUS was seen at 12 months in both women and men. In conclusion, statin therapy was effective in both genders for plaque stabilization at 12-month follow-up. High-intensity statin therapy may be particularly important in men.