Introduction: The inflammatory response occurs after aneurysmal subarachnoid hemorrhage could be a predictor of prognosis in aneurysmal subarachnoid hemorrhage. Objectives: To comment on the relationship of admission leukocyte count with outcome in aneurysmal subarachnoid hemorrhage at Thai Nguyen National Hospital. Methods: a cross-sectional descriptive study was conducted on 45 Aneurysmal Subarachnoid Hemorrhage were treated in the Stroke Center of Department of Neurology at Thai Nguyen National Hospital. Results: The average admission white blood cell (WBC) count was 14,25±4,25 (G/L), the rate of Neutrophil-to-Lymphocyte was 12,56±9,9; The average mRankin score (mRS) at discharge from the hospital was 2,13±2,48, mRS score 0-2 was 68,9% ; The high neutrophil to lymphocyte ratio is associated with poor outcome in aneurysmal subarachnoid hemorrhage. Conclusion: The high neutrophil to lymphocyte ratio on admission is associated with poor outcome in aneurysmal subarachnoid hemorrhage.