Objective:To investigate the predictive value of neutrophil/lymphocyte ratio (NLR) at admission for stroke associated pneumonia (SAP) in patients with acute ischemic stroke (AIS).Methods:Patients with AIS admitted to the First Affiliated Hospital of Kunming Medical University from January 2019 to June 2020 were retrospectively included. The demographic information, vascular risk factors, severity of stroke at admission, and NLR data of the patients were collected. Multivariate logistic regression was used to analyze the independent correlation between NLR and SAP. The NLR was divided into quartile groups to further analyze the trend relationship between NLR and SAP. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of NLR for SAP. Results:A total of 316 patients with AIS were enrolled, including 200 males (63.29%) with an age of 63.86±13.78 years. The median baseline Nationanl Institutes of Health Stroke Scale score was 4 (interquartile range, 2-9), and the median NLR was 4.42 (interquartile range, 3.17-6.70). Ninety-three patients (29.43%) experienced SAP. Multivariate logistic regression analysis showed that NLR was an independent risk factor for SAP in patients with AIS (odds ratio 1.189, 95% confidence interval 1.077-1.313; P<0.001). Moreover, SAP risk increases with the increase of NLR ( Ptrend<0.001). Compared to the first quartile, the risk of SAP increased 9.991 times in the fourth quartile (95% confidence interval 2.912-34.279; P<0.001). ROC curve analysis showed that the area under the curve of NLR for SAP prediction was 0.793 (95% confidence interval 0.737-0.850), with an optimal cutoff value of 5.475. The sensitivity and specificity for predicting SAP were 66.67% and 79.82%, respectively. Conclusion:NLR at admission is an independent risk factor for SAP in patients with AIS and has certain predictive value for SAP.