Objective To investigate the value of ischemia-modified albumin (IMA) in evaluating delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH) and its association with patient prognosis.Methods A total of 198 patients with aSAH were enrolled, and according to the presence or absence of DCI, these patients were divided into DCI group and non-DCI group. Serum IMA was measured, and transcranial Doppler was used to monitor the mean blood flow velocity of the middle cerebral artery (VMCA). The incidence rate of cerebral vasospasm (CVS) and serum IMA were compared between the two groups.Results VMCA and serum IMA reached the peak on days 7-10, followed by a gradual reduction. There were significant differences in VMCA and serum IMA across days 1-6, 7-10, and 11-14 (P<0.05). Compared with the non-DCI group, the DCI group had significantly higher incidence rate of CVS and serum IMA level (P<0.05). The poor prognosis group had a significantly higher serum IMA level than the good prognosis group (64.28±5.94 U/ml vs 45.46±5.72 U/ml, P<0.05).Conclusions Serum IMA level is closely associated with CVS and prognosis, and to a certain extent, it can reflect the severity of cerebral ischemia after aSAH. The evaluation of vasospasm-related DCI has an important value in prognosis prediction.