Objective To explore the effect of intensive statin therapy on clinical outcomes in patients with acute coronary syndrome (ACS). Methods A total of 546 ACS patients diagnosed at the First Medical Center of Chinese PLA General Hospital between April 2013 and April 2014 were enrolled in this study. According to their initial statin dose, they were divided into common treatment group (n=431) and intensive treatment group (n=115). The general data and clinical outcomes were compared between the 2 groups. SPSS 17.0 was applied for statistical analysis. Depending on the data types, student′s t test or Chi-square test was employed for intergroup comparison. Cox regression model was used to analyze the risk factors affecting the prognosis of patients. Results The longest follow-up period was 5 years, and the median time was 4.3 years. There were 13 (2.38%) patients who died during follow-up, including 12 (2.20%) due to cardiac causes and 1 (0.18%) to pulmonary infection. The incidences of angina [6.96% (8/115) vs 28.54% (123/431)] and major adverse cardiovascular events (MACE) [18.26% (21/115) vs 32.71% (141/431)] was significantly lower in the intensive treatment group than the common treatment group (all P<0.05). Cox multiple regression analysis showed that history of diabetes (OR=1.533,95%CI 1.131-2.077; P=0.006) and age (OR=1.003,95%CI 1.001-1.031; P=0.037) were significant risk predictors for MACE in ACS patients. Conclusion ACS patients complicated with diabetes mellitus are at high risk of MACE, and intensive statin therapy can reduce the incidence.