Subarachnoid hemorrhage (SAH) strikes individuals with devastating neurological results. Traditional viewpoints do not explain all the differences that are usually found in clinical practice. The role of genetic predisposition in SAH has recently been investigated. Particular attention has been paid to the apolipoprotein E (apoE) genotype. APOE genotype is a major prognostic factor in patient outcome after spontaneous aneurysmal SAH. In patients with SAH, the expression of the apoE ε4 allele is associated with a higher risk of negative outcome and delayed ischemia. Evidence from experimental and clinical studies confirms that apoE plays an important role in the pathological events after SAH. This article reviews related research and surveys the links between the pathological events of SAH and apoE.