Abstract: Objective Study on the relationship between neutrophil count and no-reflow phenomenon in patients with ST-segment elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI). Methods We retrospectively reviewed 204 consecutive patients with STEMI undergoing primary PCI within 12 h from symptom onset between August 2016 to December 2017 at the cardiology department of our hospital. The patients were divided into two groups: no-reflow and normal-reflow. The neutrophil counts and other laboratory parameters were measured on admission before PCI. Multivariate logistic regression analysis was used to identify independent predictors for the development of the no-reflow phenomenon. Results There were 39 patients (19.12%) in the no-reflow group and 165 patients in the normal-reflow group. Compared with the normal reflow group, the age (61.2+12.8 vs. 67.8 + 10.9) of the patients without reflow group was significantly higher (P<0.05), and the level of hsCRP (3.58 vs. 8.12), cTnI peak (33.69 vs. 65.47) and neutrophils count (6.25×109/L vs. 7.35×109/L) were all higher (P<0.05). In the multivariate analysis, age (OR=1.038, 95%CI=1.008-1.064, P=0.017) and neutrophil count (OR=1.236, 95%CI=1.084-1.367, P=0.001) were independent predictors of no complex flow. Conclusions Neutrophil counts on admission was independent clinical predictors of no-reflow following primary PCI in patients with STEMI. Such data can be used in risk estimation of the no-reflow phenomenon and tailoring preventive strategies promptly to at-risk patients.