Abstract: Objective To investigate the relationship between neutrophil count and no-reflow phenomenon in patients with ST-segment elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI). Methods The clinical data of 204 patients with STEMI who underwent PCI within 12 h after the onset of symptoms were collected and divided into no-reflow group (n=39) and normal reflow group (n=165). Neutrophil counts and other hematological parameters were measured at admission. Multivariate Logistic regression analysis was used to determine independent predictors of no-reflow phenomenon. Results Compared with the normal reflow group, the age of the no-reflow group was significantly older ［(67.8±10.9) years vs. (61.2±12.8) years, P<0.05), and the high-sensitivity C-reactive protein (hsCRP) level (81.23 mg/L vs. 35.82 mg/L), the peak of troponin (cTnI) (65.47 μg/L vs. 33.69 μg/L) and neutrophil count (7.35×10⁹/L vs. 6.25×10⁹/L) were significantly higher (P<0.05). The multivariate analysis indicated that age (OR=1.038, 95% CI: 1.008-1.064, P<0.05) and neutrophil count (OR=1.236, 95% CI: 1.084-1.367, P<0.01) were independent predictors of no-reflow phenomenon. Conclusions The neutrophil count at admission is closely related to the occurrence of no-reflow after PCI. It can be used for risk assessment of no-reflow in STEMI patients, and timely prevention strategies can be developed for high-risk patients.