Background: Cerebral vasospasm remains a significant cause of morbidity and mortality in patients after aneurysmal subarachnoid hemorrhage (aSAH). Recently, there has been growing interest in the associations between development of vasospasm and inflammatory cytokines, leukocytes, and pro-thrombotic pathways. Thus far, these investigations have been confined to the prediction of vasospasm and delayed cerebral ischemia rather than the prediction of clinical outcome. We aimed to identify various hematologic predictors of clinical outcome in patients diagnosed with cerebral vasospasm following aSAH. Methods: All aSAH patients between 2009-2016 at our institution were reviewed. Patients with symptoms and radiographic evidence of cerebral vasospasm were identified. We assessed baseline and outcome data, including patient demographics, initial aneurysm specifications, management of aSAH and subsequent vasospasm(s), hematologic variables, and 90-day functional outcome (modified Rankin Scale 0-6). Results: One-hundred-ten patients with cerebral vasospasm were identified. Forty-three patients had a mRS score of 3-6 at 90 days following discharge. In multivariate logistic regression analysis, lymphocyte count on day of aSAH (OR=4.82, CI 95% 1.68—13.89), high Hunt-Hess grade (OR=4.23, CI 95% 1.19—15.03), external ventricular drain use (OR=11.18, CI 95% 1.27—98.42), and severe vasospasm (OR=8.25, CI 95% 2.26—30.13) were found to be predictors of poor clinical outcome. Conclusions: Elevated lymphocyte count following aSAH was associated with a significantly higher rate of poor clinical outcome in patients who developed vasospasm. Several studies have focused on various inflammatory markers, but little attention has been paid to lymphocyte count. Closer monitoring with a lower threshold for endovascular treatment may be indicated in this patient population and could improve clinical outcomes.