INTRODUCTION: The subarachnoid hemorrhage due to a ruptured brain aneurysm is a neurological emergency with high mobility and mortality. Hypertensive states are related to a bad prognosis and a higher risk of a ruptured aneurysm. However, the relationship between the blood pressure variability with the aneurysmal subarachnoid hemorrhage and its prognosis is quite unknown. EVIDENCE ACQUISITION: A systematic review was performed across the databases. The following descriptors and related were used for the search: blood pressure, arterial pressure, variability, subarachnoid hemorrhage, hemorrhage, aneurysmal, aneurysmal subarachnoid hemorrhage. The following data were extracted: Glasgow Outcome Scale or Modified Rankin Scale, and blood pressure variabilities to categorize the prognosis. EVIDENCE SYNTHESIS: Five studies were selected. The blood pressure variability and the related outcome were assessed by mean systolic blood pressure and minimum systolic blood. The meta-analysis of mean systolic blood pressure (cut-off >95.3 mmHg) showed an odds ratio of 11.23 (95% CI: 4.423 to 28.537) (P≤0.001), predicting the good outcome after the aneurysmal subarachnoid hemorrhage. The pooled analysis revealed AUC of the ROC predicting the good outcome was statistically significant (AUC: 0.85, P<0.001). The pooled data analysis of minimum systolic blood pressure revealed an odds ratio of 6.43 (95% CI: 2.834-14.589, P<0.001) and AUC of the pooled ROC 0.931 (95% CI: 0.851 to 1.000, P<0.001) to predict poor outcome. The funnel plot through Egger's test for the analysis showed different grades of asymmetry. CONCLUSIONS: The blood pressure variability (mean and minimum systolic blood pressure) is a good predictor and parameter in the aneurysmal subarachnoid hemorrhage prognosis and outcome prediction.