α-HBDH serves as a biomarker of myocardial damage and is implicated in adverse outcomes across various critical illnesses. Our study aimed to assess the correlation between α-HBDH levels, and severity and recurrence of acute ischemic stroke (AIS).We enrolled patients with mild-to-moderate AIS within 72 h of onset. Based on the baseline score of the National Institutes of Health Stroke Scale (bNIHSS) at registration, patients were categorized into mild (bNIHSS ≤ 4 points) and moderate AIS groups (4 < bNIHSS ≤ 10 points). Subsequently, based on the normal upper limit of α-HBDH, patients were divided into low-level α-HBDH (≤ 180 U/L) and high-level α-HBDH (> 180 U/L) groups. Multivariate logistic regression analysis and Cox proportional hazard regression analysis were employed to evaluate the relationship between α-HBDH levels and bNIHSS scores as well as the risk of recurrent AIS within 90 days.We observed a significant association between higher baseline levels of α-HBDH and increased bNIHSS scores, indicating a more severe AIS (odds ratio = 24.449; 95% confidence interval [CI], 8.749-68.324; p < 0.01). Additionally, the risk of recurrent AIS within 90 days was 4.666 times higher in the high-level α-HBDH group compared to the low-level group (hazard ratio = 4.666; 95% CI, 2.481-8.777; p < 0.01).The baseline level of α-HBDH is significantly correlated with the severity of AIS and the risk of recurrent AIS within 90 days.© 2024. The Author(s).