Background: Only a few non-recent studies assessed the importance of hematocrit (HCT) in patients with ischemic stroke. We evaluated how HCT might affect early mortality after stroke. Methods: We investigated all first-ever ischemic strokes included in the population-based L'Aquila registry. 3,481 patients according to HCT (%) values were included into four categories ( <= 40, 41 - 45, 46 - 50, and > 50). Results: There were more men than women with HCT 1 50 ( 6.6 vs. 2.8%; p < 0.0001) and more women than men with HCT <= 40 (48.5 vs. 37.9%; p < 0.0001). Proportions of chronic atrial fibrillation ( p = 0.0053) increased in women from the lower to the higher HCT categories. 7- and 28- day case-fatality rates were similar in men and women in the lower HCT categories but higher in women than in men in the higher categories. At the 28- day Kaplan-Meier analysis, men had similar survivals in the different categories while women with HCT 1 50 showed the worst survival (p < 0.0001). At the multivariate Cox regression analysis HCT 46 - 50 and 1 50 was an independent predictor of mortality in women within 28 days. Conclusion: High HCT might represent in women a previously underestimated independent predictor of mortality after ischemic stroke. Consideration of HCT in future stroke trials would be useful for ameliorating stroke care, especially in women.