Objective : Stroke is one of the most common causes of death in Korea. This study was done to evaluate the association of complete blood count (CBC) with the risk of hemorrhagic stroke and ischemic stroke. Methods : In 217-case patients with ischemic stroke or hemorrhagic stroke and 146 healthy control subjects without stroke, hypertension, diabetes mellitus, hyperlipidemia, or ischemic heart disease and 160 controls without ischemic stroke or hemorrhagic stroke, we tested and compared white blood cell count (WBC), red blood cell count (RBC), hemoglobin (Hgb), hematocrit (Hct) and platelet. These data were statically analyzed by general linear models and binary logistic regression analysis to get each adjusted odds ratio. Results :The level of WBC was significantly higher in all cases. The level of RBC, Hct and Hgb was significantly lower in patients of ischemic stroke. The level of platelet was significantly higher in patients of ischemic stroke. Conclusion : These results suggest high WBC may be a risk factor of hemorrhagic stroke and ischemic stroke and low RBC, low Hct, low Hgb and high platelet may be risk factors of ischemic stroke in Koreans.