Background: Predictors of outcomes following endovascular treatment (ET) for aneurysmal subarachnoid hemorrhage (aSAH) are not well-defined. Identifying them would be beneficial in determining which patients might benefit from ET. Objective: To identify the predictive factors for poor outcomes following ET for aSAH. Methods: 120 patients with ruptured cerebral aneurysms underwent endovascular embolization between January 2017 and December 2018. Blood pressure variability was examined using the standard deviation of the 24-hour systolic blood pressure (24hSSD) and 24-hour diastolic blood pressure (24hDSD). Predictors were identified through univariate and multivariate regression analysis. All patients were followed up for three months. Results: At follow-up, 86 patients (71.7%) had good outcomes and 34 (28.3%) had poor outcomes. Patients with poor outcomes had significantly higher 24hSSD than those with good outcomes (19.3 ± 5.5 vs 14.1 ± 4.8 mmHg; P < 0.001). The 24hDSD did not differ significantly between patients with good outcomes and those with poor outcomes (9.5 ± 2.3 vs 9.9 ± 3.5 mmHg; P = 0.464). The following were significant risk factors for poor outcomes after endovascular embolization: age ≥ 65 years (odds ratio [OR] = 23.0; 95% confidence interval [CI]: 3.0-175.9; P = 0.002); Hunt-Hess grade 3-4 (OR = 6.8; 95% CI: 1.1-33.7; P = 0.039); Fisher grade 3-4 (OR = 47.1; 95% CI: 3.8-586.5; P = 0.003); postoperative complications (OR = 6.1; 95% CI: 1.1-34.8; P = 0.042); and 24hSSD ≥ 15 mmHg (OR = 14.9; 95% CI: 4.0-55.2; P < 0.001). Conclusion: Elevated 24hSSD is a possibly treatable predictive factor for poor outcomes after ET for aSAH.