Objective To explore the relationship between neutrophil-to-lymphocyte ratio (NLR) and percutaneous coronary intervention (PCI) in the patients with unstable angina pectoris (UAP). Methods A total of 260 UAP patients admitted to the Department of Cardiology of the First Affiliated Hospital of Henan University of Science and Technology from January 2018 to June 2019 were enrolled in this study. According to the results of coronary angiography, they were divided into PCI group (n=167) and the group without the need for the procedure (n=93). The clinical data were collected and compared between the two groups. SPSS statistics 24.0 was used for data processing. Logistic regression analysis was employed to analyze the risk factors for PCI in UAP patients. Receiver operating characteristic (ROC) curve was plotted to analyze the diagnostic value of NLR for UAP patients who needed PCI. Results There were statistical differences between the two groups in age, gender, history of diabetes mellitus, neutrophil count, levels of total cholesterol(TC), high-density lipoprotein cholesterol(HDL-C) and low-density lipoprotein cholesterol(LDL-C), and NLR (P<0.05). Spearman correlation analysis showed that NLR was positively correlated to the necessity of PCI in UAP patients (r=0.353, P<0.001). Multivariate logistic regression analysis indicated that NLR was independent risk factor for PCI in UAP patients (OR=1.982, 95%CI 1.168～3.362). ROC curve showed that the area under the curve of NLR in the diagnosis of unstable angina requires PCI treatment was 0.719 (95%CI 0.651～0.776). Conclusion NLR can be regarded as one of the predictors for PCI in UAP patients.