Aim:To evaluate the diagnostic and prognostic significance of miRNA signatures by identifying differences in miRNA expression between ruptured and unruptured intracranial aneurysm (IA) cases, as well as to pinpoint miRNAs that correlate with clinical severity in patients with aneurysmal subarachnoid hemorrhage (aSAH).Material and Methods:Peripheral blood samples were collected from 50 IA patients (25 without rupture and 25 with rupture) and 25 healthy controls. In the ruptured group, analyses were performed on samples collected on Days 3 and 5 after SAH. The clinical severity and outcomes of the disease were assessed using Fisher grades, WFNS grades, Hunt–Hess grades, and the Modified Rankin Scale.Results:We found that the expression levels of miR-21-5p and miR-15a were significantly altered in unruptured aneurysms (UA) patients compared to controls. The expression levels of 10 miRNAs were significantly decreased in ruptured aneurysms (RA) patients compared to controls. The ruptured group also exhibited an upregulation of 16 miRNAs relative to the unruptured group. Furthermore, we noted a significant increase in miR-24 expression in RA patients between Days 3 and 5, suggesting its potential role in the progression of aSAH. miR-9p-3p and miR-497 were found to be associated with aSAH severity. Moreover, the levels of miR-451a, miR-146a-5p, miR-502-5p, and miR-497 were significantly lower in patients with poor outcomes compared to those with favorable outcomes.Conclusion:These findings suggest that specific miRNAs may serve as potential diagnostic and prognostic biomarkers for IA and subsequent SAH, particularly on Day 3 following aSAH.