Background The neutrophil-to-lymphocyte (N/L) ratio has been associated with poor outcomes in patients with cardiovascular diseases.However,limited study investigated the N/L ratio in patients with CHF.Hence we aimed to evaluate the association between the N/L ratio and the future risk of major adverse cardiovascular events (MACE) in patients with CHF.Methods Four hundred and fifty-two chronic heart failure (CHF) patients from May 2014 to May 2017 were enrolled in this study.The patients were categorized on the basis of the N/L ratio into the lower (＜ 2.9) and higher (＞ 2.90) groups.Cox regression models were used to analyze the association between the N/L ratio and major adverse cardiovascular event (MACE).The Kaplan-Meier method was used to evaluate the cumulative hazard for the events.Results A total of 452 patients (275 males,177 females,mean age 52.2 ± 14.52 years) were enrolled in this study,including the 231 patients in low N/L ratio group and 221 high in N/L ratio group.MACE occurred in 52 patients (11.5％).In univariate and multivariate analyses,the patients in the high N/L ratio group showed a higher risk for MACE (HR =1.913,95％ CI 1.512 to 2.388,P ＜ 0.001;HR =1.411,95％ CI 1.108 to 1.785,P =0.002,respectively).Conclusions Our study demonstrates that the N/L ratio measured at the time of hospital admission is associated with an increased risk for subsequent MACE.