BACKGROUND AND AIMS: It remains unclear whether serum PCSK9 levels can predict the severity of the disease and the risk of future events in patients with coronary artery disease (CAD). We aimed to evaluate the association between PCSK9 levels, metabolic parameters, severity of CAD on coronary angiography (SYNTAX score), and the risk of in-hospital events and at one-year follow-up. METHODS AND RESULTS: From September 2015 to December 2016, serum PCSK9 levels were measured on admission in patients not previously receiving statin therapy, and admitted for an acute myocardial infarction (MI), in an intensive care unit from a university hospital. In a total of 648 patients (mean age: 66 years, 67% male), median PCSK9 was 263 ng/ml, higher for females compared with males (270 vs 256 ng/ml, p = 0.009). Serum PCSK9 was associated with LDL cholesterol (r = 0.083, p = 0.036), total cholesterol (r = 0.136, p = 0.001) and triglycerides (r = 0.137, p = 0.001). A positive association was also observed in the subgroup of patients with CRP >10 mg/L (p < 0.001), but not with NT-proBNP, troponin and creatine kinase. PCSK9 levels were similar whatever the SYNTAX score or the number of significant coronary lesions. PCSK9 levels were not associated with in-hospital events (death, recurrent MI and stroke) and events (cardiovascular death, cardiovascular events, recurrent MI) at one-year follow-up. CONCLUSIONS: In this large cohort of patients hospitalized for acute MI and not previously receiving statin therapy, PCSK9 levels was not associated with the severity or the recurrence of cardiovascular events. The clinical utility of measuring PCSK9 levels for this category of patients therefore appears limited.