Objective To investigate the changes of serum neuroglobulin (NGB) levels in patients with aneurysmal subarachnoid hemorrhage (aSAH) and its clinical value in predicting of delayed cerebral ischemia (DCI). Methods A total of 217 patients with aSAH who were diagnosed and treated in the Department of Neurology of Wuwei People's Hospital from October 2019 to October 2022 were selected. They were divided into DCI group and non-DCI group according to the occurrence of DCI after aSAH. The clinical data, and serum NGB levels on day 1 and day 3 after admission were compared between the two groups, and the value of serum NGB in prediction of DCI was evaluated by ROC curve. Logistic regression was used to analyze the risk factors to DCI in aSAH patients. Results DCI occurred in 43 of 217 patients with aSAH (19.8%). Hunt-Hess grade and modified Fisher grade in DCI group were higher than those in non-DCI group (P<0.05). The level of serum NGB in DCI group was higher than that in non-DCI group on day 1 and day 3 after admission (P<0.05), and the levels of serum NGB on day 3 after admission were lower than that on day 1 in two groups (P<0.05). The decrease of serum NGB level in DCI group was lower than that in non-DCI group (P<0.05). ROC curves showed that serum NGB at 3 d after admission predicted a greater AUC for DCI (0.838) than serum NGB at 1 d after admission (0.706)(Z=2.139, P<0.05), with an optimal cutoff of 10.19 ng/ml of serum NGB, the sensitivity and specificity were 74.4% and 86.8% respectively. Logistic regression analysis showed that the risk factors of DCI in patients with aSAH were modified Fisher Grade Ⅲ-Ⅳ (OR=3.790, 95%CI 1.531-9.382), Hunt-Hess grade Ⅲ-Ⅴ(OR=2.448, 95%CI 1.023-5.858) and increased serum NGB at 3 d after admission (OR=1.835, 95%CI 1.496-2.251). Conclusions The serum NGB level is relatively high in patients with DCI after aSAH in the early stage. The serum NGB level, modified Fisher grade, and Hunt-Hess grade are related to the development of DCI after aSAH, and the serum NGB level on 3 d after admission has high predictive value.