Abstract <p>Posterior circulation ischemic stroke (PCIS) is caused by occlusion of the vertebral basilar artery, with complex and diverse symptoms. Prompt detection and prediction of risk factors can facilitate early diagnosis and positively impact patient outcomes. This study assessed the clinical relevance of miR-30e-5p in diagnosing and predicting PCIS, aiming to uncover innovative and effective biomarkers for this condition. A&#xa0;total of 115 PCIS patients and 70 healthy individuals (control) were enrolled in this study. The expression levels of miR-30e-5p in study subjects were detected using PCR. Analysis of the correlation between miR-30e-5p and the degree of vertebrobasilar artery stenosis. The ROC and Logistic regression analyses were carried out to estimate the diagnostic and prognostic value of miR-30e-5p in PCIS. This study found that compared with the healthy control group, the expression of miR-30e-5p was reduced in patients with PCIS. There was a significant correlation between the expression level of miR-30e-5p and the degree of vertebrobasilar artery stenosis. miR-30e-5p could discriminate PCIS patients from the healthy controls with high sensitivity and specificity. The miR-30e-5p downregulation could predict the poor prognosis of PCIS patients. The degree of vertebrobasilar artery stenosis is a risk factor for the adverse prognosis of PCIS patients, while serum miR-30e-5p and pc-ASPECTS are protective factors for the prognosis of PCIS patients. Therefore, miR-30e-5p can serve as a biomarker for the diagnosis and prognosis of PCIS, but its specific regulatory effects require further investigation.</p>