Background: Stroke is one of the leading causes of disability worldwide. Recently, stroke prognosis estimation has received much attention. This study investigates the prognostic role of aspartate transaminase/alanine transaminase (De Ritis, AAR), alkaline phosphatase/alanine transaminase (ALP/ALT), and aspartate transaminase/alkaline phosphatase (AST/ALP) ratios in acute ischemic stroke (AIS). Methods: This retrospective cohort study involved patients who experienced their first-ever AIS between September 2019 and June 2021. Clinical and laboratory data were collected within the first 24 hours after admission. Functional and mortality outcomes were evaluated 90 days after hospital discharge in clinical follow-up. Functional outcome was assessed by a modified Rankin Scale (mRS). The correlation between the laboratory data and study outcomes was evaluated using univariate analysis. In addition, regression models were developed to evaluate the predictive role of AST/ALP, ALP/ALT, and AAR ratios on the study outcomes. Results: Two hundred seventy-seven patients (mean age 69.10 ± 13.55, 53.1% female) were included. According to univariate analysis, there was a weak association between 3-months mRS, and both AST/ALT (r = 0.222, P < 0.001), and AST/ALP (r = 0.164, P = 0.008). Subsequently, higher levels of these ratios and absolute values of AST, ALT, and ALP were reported in deceased patients. Based on regression models adjusted with co-variable (age, gender, underlying disease, and history of smoking) AST/ALT and AST/ALP ratios had a significant independent association with 3-month mRS (CI:1.37-4.52, p = 0.003, and CI: 4.45-11,547.32, p = 0.007, respectively) and mortality (CI: 0.17-1.06, adjusted R² = 0.21, p = 0.007, and CI: 0.10-2.91, p = 0.035, adjusted R² = 0.20, respectively). Conclusions: Elevated AST/ALP and AAR ratios at admission were correlated with poorer outcomes at 3 months in patients with first-ever AIS. Prospective studies in larger cohorts are required to confirm our findings and to evaluate further whether the AST/ALP and De Ritis ratios may represent a useful tool for determining the prognosis of AIS patients.