Background and purpose Hyperglycemia in acute stroke leads to poor neurological outcomes. The role of microRNA (miRNA) in hyperglycemia‐associated genes can provide new avenues for stroke prognostic applications. We aimed to identify novel genes and their regulated miRNAs that are associated with hyperglycemia‐induced unfavorable stroke outcomes and further validated in the plasma exosome. Moreover, we intended to evaluate the prognostic ability of miRNA–messenger RNA (mRNA) biomarkers in addition to using traditional risk factors. Methods After the integration analysis of small RNA sequencing and mRNA polymerase chain reaction array, two mRNAs and six miRNAs were selected for validation in middle cerebral artery occlusion animal models and ischaemic stroke patients. Receiver operator characteristic analysis was used to determine the performance of mRNA and miRNA expression. Results The increased Fas expression was associated with hyperglycemia after acute stroke onset in animal and human studies. In addition, Fas gene level was significantly higher in patients with an unfavorable outcome when compared with patients with a favorable outcome. The expression of Fas and miRNA hsa‐let‐7b‐5p in addition to traditional risk factors could increase the discrimination and predictive ability for poor prognosis. The higher exosomal Fas was further observed among patients with an unfavorable outcome, suggesting Fas signal transporting through exosome in the circulation system. Conclusions Combined analyses of Fas and has‐let‐7b‐5p expression in addition to traditional risk factors are favorable prognostic biomarkers for predicting poor neurological outcomes at 3 months after stroke onset in ischaemic stroke patients. Additional studies are required to address the precise role of the apoptosis pathway in unfavorable hyperglycemia‐induced stroke outcomes.