The prognosis of patients with subarachnoid hemorrhage is influenced by many factors. Neuron-specific enolase (NSE) is a biological marker of neurological damage. This study aimed to determine the related prognostic factors and whether or not the maximum NSE value (NSEmax) has a threshold between good and poor prognosis in aneurysmal subarachnoid hemorrhage (aSAH).A total of 259 patients admitted following aSAH were treated by appropriate methods. Initial neurological severity was evaluated by using the initial Glasgow coma scale and Hunt-Hess grades. NSE plasma concentration was measured during the patient's stay in the neurosurgical intensive care unit, and NSEmax was selected for further study. The primary endpoint of the study was Glasgow outcome score (GOS), which was dichotomized as poor outcome (GOS 1-3) or good outcome (GOS 4-5) at discharge.A poor outcome of patients with aSAH at discharge was associated with mild hypothermia treatment, Hunt-Hess grade, rehemorrhagia, neurogenic pulmonary edema, and pneumonia, which were independent risk factors affecting the prognosis of patients. The best threshold of the maximum value of NSE for poor or good prognosis was 26.255 μg/L (specificity 0.908).Poor neurological score, pulmonary complications, aneurysm rerupture, and mild hypothermia indicate a poor prognosis. NSEmax>26.255 μg/L is an independent predicting factor of poor neurological outcome at discharge after aSAH. This threshold value could help clinicians make the appropriate decision and prognosis.Copyright © 2022 Hao Zhao et al.