Background: Cardiac enzymes such as creatine kinase-MB, troponin I, and brain natriuretic peptide (BNP) are thought to be useful prognostic factors in patients with acute ischemic stroke. This study investigated the efficacy of cardiac biomarkers as prognostic factors. Methods: We reviewed patients with acute ischemic stroke whose cardiac biomarkers had been measured and who were admitted to our hospital between January 2012 and December 2013. The cardiac biomarkers were measured within 24 hours after admission to the emergency room. We evaluated the clinical characteristics and compared the outcomes of the patients based on their cardiac biomarkers. Results: The following cardiac biomarkers were measured in 219 patients with acute ischemic stroke: creatine kinase-MB (n=218), troponin I (n=219), and BNP (n=143). Statistically significant differences were observed in older age (68.77±12.42 vs. 74.59±6.68, p<0.05), insula involvement (30.5% vs. 59.1%, p<0.01), and higher BNP (259.75±422.65 vs. 667.06±1093.22, p<0.01). Conclusions: These results suggest that measuring all cardiac biomarkers may be not effective in determining the prognosis of acute ischemic stroke. However, BNP may be a superior to troponin I in predicting the prognosis.