Objective To investigate the value of cerebral perfusion pressure (CPP) in predicting delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH).Methods A total of 50 patients with aSAH who attended our hospital and underwent CPP test from January to December, 2016, were enrolled, among whom 19 patients developed DCI. The total proportion of time below each CPP threshold was calculated for all patients and the receiver operating characteristic (ROC) curve and the binary logistic regression analysis were used to investigate the correlation between CPP and DCI.Results The thresholds for the proportion of time with a CPP of below 50 mmHg, 55 mmHg, 60 mmHg, and 65 mmHg in predicting DCI were 0.28% (area under the ROC curve[AUC]=0.778), 3.0% (AUC=0.756), 10.8% (AUC=0.749), and 16.1% (AUC=0.718), respectively, and the binary logistic regression analysis showed that these thresholds were associated with DCI (P<0.05). The thresholds for the proportion of time with a CPP of below 70 mmHg, 75 mmHg, and 80 mmHg were 24.8% (AUC=0.697), 49.6% (AUC=0.686), and 55.9% (AUC=0.672), respectively, and the binary logistic regression analysis showed that these thresholds were not associated with DCI (P>0.05).Conclusions The risk of DCI in patients with aSAH is associated with the reduction in CPP, and CPP maintained above 70 mmHg may help to prevent DCI.