Using serial intravascular ultrasound (IVUS), we evaluated the natural evolution of non-culprit/non-target lesion ruptured coronary plaques and assessed the impact of statin therapy. Twenty-eight patients with non-stenotic ruptured plaques underwent baseline and 12-month follow-up IVUS studies; half were treated with statins. Standard IVUS analyses were performed. Complete healing of ruptured plaques was observed in four (29%) statin-treated patients and no non-statin-treated patients (p=0.049). Statin-treated patients had an increase in lumen area of 0.4+/-0.8 mm2 (versus a decrease in lumen area of -0.6+/-1.0 mm2 in non-statin-treated patients, p=0.007) and no change in plaque area (versus an increase in plaque area of 0.6+/-0.9 mm2, p=0.051). During 1-year follow-up, target lesion revascularization was performed in three non-statin-treated patients (21%) and no statin-treated patient (p=0.11). Compared to lesions that did not require revascularization, lesions requiring revascularization had a decrease in lumen area (-1.7+/-1.4 mm2 versus 0.1+/-0.8 mm2, p=0.001) as well as an increase in plaque area (1.6+/-1.0 mm2 versus 0.1+/-0.7 mm2, p=0.002). In conclusion, the current observational follow-up IVUS study showed beneficial effects of statin treatment on reduction of revascularization rates and stabilization of non-culprit/non-target lesion plaque ruptures without significant stenosis. Conversely, healing of non-statin-treated non-culprit/non-target lesion plaque ruptures can be responsible for lesion progression requiring revascularization.