Objective To explore the risk factors of early neurological deterioration (END) and hemorrhagic transformation (HT) in the patients with posterior circulatory ischemic stroke (PCIS) . Methods A total of 280 PCIS patients were retrospectively enrolled in the Department of Neurology of Yizheng People′s Hospital from January 2017 to December 2019. According to the changes of National Institutes of Health Stroke Scale (NIHSS) within 72 hours of admission, the patients were divided into the END group and the non-END group, and according to the imaging records, the HT group and non-HT group. SPSS statistics 25.0 was used for data analysis, and multivariate logistic regression was used to determine the independent risk factors of END and HT. Results Baseline NIHSS score (OR=2.246,95%CI 1.082-4.662; P=0.030) and fasting blood glucose (OR=2.440,95%CI 1.205-4.939; P=0.013), uric acid (OR=15.310,95%CI 1.978-118.476; P=0.009), smoking (OR=5.556,95%CI 2.645-11.668; P=0.000) were independent risk factors for END. Baseline NIHSS score (OR=7.923,95%CI 1.377-45.597; P=0.020), fasting blood glucose (OR=8.160,95%CI 1.543-43.159; P=0.013) and high-sensitivity C-reactive protein (OR=8.529,95%CI:1.750-41.554; P=0.008) were independent risk factors for HT. Conclusion Higher baseline NIHSS score and fasting blood glucose were independent risk factors for END and HT in PCIS patients. Smoking and high uric acid levels were associated with END. Serum hs-CRP elevation is associated with HT.