Background: Shock index (SI) has been reported to help us predict adverse prognosis in patients with acute ischemic stroke (AIS). However, the prognostic value of age SI and age modified shock index (MSI) in acute ischemic stroke is unknown. In our study, we aimed to examine the association between the severity of the stroke and in-hospital mortality, age SI and age MSI in patients with AIS. Methods: A total of 256 patients were enrolled in this study. The National Institutes of Health Stroke Scale (NIHSS) was used to determine the severity of stroke. Patients were divided into two groups according to the NIHSS score calculated during hospitalization (NIHSS>14: severe disability group, NIHSS<15: moderate and mild disability group). Shock indexes were calculated using the blood pressure and heart rate values measured as a result of the cardiovascular examinations of the patients. We looked for correlations between increased NIHSS and in-hospital mortality with age shock index and age modified shock index. Results: : Age SI and age MSI values were higher in the severe disability group than those without severe disability, and the results were statistically significant (p<0.001, p<0.001, respectively). Also, a positive correlation was determined between the height of NIHSS and the age SI and the age MSI (p=0.002, r=0.197, p=0.001, r=0.215, respectively). Thirty-two (12.5%) of 256 patients included in the study died during hospitalization. Patients who died were older (77.1±11.0 vs. 67.5±13.5, respectively; p<0.001). According to Point-Biserial correlation analysis, there was a positive correlation between mortality and age SI, and age MSI (p<0.001, r=0.258 ve p<0.001, r=0.274, respectively). Conclusions: : As a result of our study, the relationship between stroke severity and increasing age SI and age MSI was significant and there was a positive correlation. In addition, there was a significant and positive relationship between in-hospital mortality and age SI and age MSI.