Background: Evolocumab has been demonstrated to significantly reduce ischemic cardiovascular events in patients with stable coronary heart disease. However, it is currently unclear whether this benefit extends to patients with acute coronary syndrome (ACS) and multivessel disease (MVD) undergoing percutaneous coronary intervention (PCI). The objective of this study was to assess the safety, efficacy and feasibility of the early addition of evolocumab to statin treatment for ACS patients with MVD undergoing PCI. Methods: The authors conducted a multicenter, retrospective cohort study involving 1199 ACS patients with MVD undergoing PCI and with elevated low-density lipoprotein cholesterol (LDL-C) levels. Patients were divided into an evolocumab group or a standard-of-care group based on evolocumab use or not. The 18-month primary efficacy endpoint was a composite of ischemic stroke, death from cardiac causes, recurrent myocardial infarction (MI), unplanned coronary revascularization or unstable angina requiring hospitalization. The principal secondary efficacy endpoint was a composite of ischemic stroke, death from cardiac causes or recurrent MI. Results: After propensity score matching, the addition of evolocumab to statin treatment lowered LDL-C levels by 42.62% compared with statin therapy alone at 18 months, from a mean baseline level of 3.37–0.75 mmol/L (p 0.001). Relative to standard therapy, evolocumab added to statins was associated with significant reductions in the primary efficacy endpoint (8.3% vs. 13.3%; adjusted hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.39 to 0.91; p = 0.017) and the principal secondary efficacy endpoint (6.1% vs. 10.2%; adjusted HR, 0.61; 95% CI, 0.37 to 0.99; p = 0.048) after multivariable Cox regression adjustment. The treatment effect of evolocumab was consistent across all prespecified subgroups. There were no significant between-group differences in terms of adverse events. Conclusions: In ACS patients with MVD taken for PCI, early initiation of evolocumab along with statin treatment was associated with a significant reduction in LDL-C levels and a reduced risk of recurrent cardiovascular events. Clinical Trial Registration: Chinese Clinical Trials Registry, identifier ChiCTR2000035165. Date: 2 August 2020. URL: https://www.chictr.org.cn/.