© The Author(s) 2012The predictive value of leukocyte counts has been reported in patients with acute myocardial infarction (AMI). We aimed to evaluate the predictive value of the total leukocyte count and neutrophil-lymphocyte (N/L) ratio for mortality due to AMI. A total of 522 patients with acute ST-elevated MI were included in the study. The study population was divided into tertiles based on admission N/L ratio values. High (n = 174) and low N/L (n = 348) ratio groups were defined as patients having values in the third tertile (>5.77) and lower 2 tertiles (≤5.77), respectively. The high N/L ratio group had a significantly higher incidence of in-hospital cardiovascular mortality (13.8% vs 4.6%, P < .001). An N/L ratio >5.77 was found to be an independent predictor of in-hospital cardiovascular mortality (hazard ratio: 3.78, 95% confidence interval: 1.71-8.30, P = .001). A high N/L ratio is a strong and independent predictor of in-hospital cardiovascular mortality of AMI with ST elevation.