Abstract: Objective To investigate the role of NT-proBNP in etiology classification and risk stratification of patients with acute ischemic stroke. Methods A total of 587 patients with acute ischemic stroke admitted to Henan people's Hospital from January 2016 to December 2018 were collected prospectively. At the same time of emergency evaluation, NT proBNP was detected quickly beside the bed, and the etiology was classified. The large-artery atherosclerosis(LAA), cardioembolism(CE), small-artery occlusion(SAO), stroke of other determined etiology(SOE) and stroke of other undetermined etiology(SUE) were compared. Results There were 332 acute ischemic stroke patients met the study criteria [mean age 68.67±15.68 years, 181(54.52%) male], including 119(35.84 %) with LAA, 85(25.60 %) with CE, 91(27.41 %) with SAO and 37(11.14 %) with SOE or SUE. The age, previous cardiac disease, atrial fibrillation, SSS score on admission ≤25 and mRS ≥3 at discharge in the CE patients were significantly higher than those in other subtypes(statistics in the order were F=3.336, χ²=5.883, corrected χ²=0.015, χ²=74.755 and χ²=48.166, all P<0.001). The NT proBNP level in CE group was(798.81±347.39) pg/mL, which was significantly higher than LAA group [(421.55±178.74) pg/mL], SAO group [(390.89±195.59) pg/mL] and other group [(442.93±184.45) pg/mL, statistics in the order were t=17.163, t=20.411 and t=15.810, all P<0.001]. The optimal cut-off value of the plasma NT proBNP between CE and non-CE were 579.29 pg/mL, the sensitivity and specificity were 76.5% and 85.3%, respectively. Conclusion The level of plasma NT-proBNP of patients with CE was significantly higher than that of other subtypes. When the level of NT proBNP exceeds 579.29 pg/mL in patients with acute stroke, we should be alert to whether it is CE subtype, and the diagnosis and treatment decision should be combined with clinical comprehensive evaluation.