<p>Delayed cerebral ischemia(DCI) is a major contributor to poor outcomes after aneurysmal subarachnoid hemorrhage(SAH), primarily due to symptomatic vasospasm. Accurate early risk stratification is essential for optimizing monitoring and treatment. Two commonly used predictors are the World Federation of Neurosurgical Societies(WFNS) clinical grade and the modified Fisher radiographic grade. We assessed whether the simple arithmetic sum of these two scores—termed the “Plus score”—could improve the prediction of DCI and mortality. We retrospectively reviewed the consecutive patients treated with surgical clipping at a single tertiary center from 2021 to 2025. Inclusion required angiographically confirmed aneurysmal hemorrhage, clipping within 72 h, and ≥ 6 months of follow-up. DCI was defined as a new neurological deterioration between post-SAH day 3–15, excluding the other causes. Logistic regression and receiver operating characteristic(ROC) analysis were used to compare the predictive performance of the WFNS grade, modified Fisher grade, and Plus score. Fifty-nine patients (mean age 53 ± 14 years; 52% female) were included. DCI occurred in 32 patients(54%), and in-hospital mortality was 16.9%. The mean Plus score was significantly higher in patients with DCI than those without, and higher in non-survivors than survivors. The Plus score showed superior predictive value for DCI (AUC = 0.748; cutoff ≥ 4.5: sensitivity = 84.4%, specificity = 55.2%) compared to WFNS (AUC = 0.704) and modified Fisher (AUC = 0.703) scores. For mortality prediction, the Plus score had an AUC of 0.870. The Plus score, combining neurological and radiographic severity into a single value, offers improved risk prediction for DCI and moderate accuracy for mortality. Its simplicity and clinical accessibility make it a valuable bedside tool for early stratification and targeted care in patients with aneurysmal subarachnoid hemorrhage.</p> Graphical Abstract <p></p>