The authors hypothesized that divergent influences of the APOE epsilon4 allele on ischemic and hemorrhagic stroke survival might result from differences in coagulation profiles. In 49 hemorrhagic stroke patients, epsilon4 carriers had higher partial thromboplastin time ratios (p < 0.01) than non-epsilon4 carriers. Among 529 ischemic stroke patients, increasing epsilon4 allele dose was associated with improved survival (p = 0.03) after adjusting for baseline NIH stroke scale (p = 0.00001) and partial thromboplastin time ratio (p = 0.01). Relative anticoagulation does not fully explain the survival advantage in epsilon4-carrying ischemic stroke patients.