Objective Compared the effect of atorvastatin 10 mg combined ezetimibe 10 mg therapy with atorvastatin 20 mg on the long-term outcomes in very elderly patients with acute coronary syndrome. Methods A total of 230 octogenarian patients with acute coronary syndrome underwent coronary angiography were randomized to combined therapy group (atorvastatin 10 mg/d and ezetimibe 10 mg/d, n= 114) or double-dose atorvastatin group (atorvastatin 20mg/d, n= 116). The primary end point was one-year incidence of major adverse cardiovascular events (including cardiac death, spontaneous myocardial infarction, unplanned revascularization). Result At the end of one year, the percentage of patients with low-density lipoprotein cholesterol level decreased more than 30% or 50%were comparable between the two groups (93.5% vs. 90.1%, p= 0.36; 54.6% vs. 49.6%, p= 0.45). The rate of major adverse cardiovascular events in combined therapy group was similar with double-dose atorvastatin group (23.2% vs. 19.8%, p= 0.55). In COX regression model, the risk of major adverse cardiovascular events in combined group isn't significantly higher than double-dose atorvastatin group (HR [95% CI] 1.12 [0.51 to 2.55], p = 0.74). The patients whose alanine aminotransferase increasing more than upper normal limit in combined group was lower than double-dose atorvastatin group (2.8% vs. 9.0%, p = 0.05). Conclusions For very elderly patients with acute coronary syndrome, atorvastatin combining ezetimibe induced similar long-term outcomes compared with double-dose atorvastatin but with less liver dysfunction.