Subarachnoid hemorrhages (SAH) result in hemodynamic and metabolic abnormalities. The successful treatment of these abnormalities requires active treatment of neuroprotection. Recently, it has been known that albumin has important roles in neuroprotection as well as in hemodilution. We retrospectively studied 64 patients who were treated surgically for aneurysmal SAH to investigate the relationship between serum albumin levels, severity of disease and neurological outcomes. A high proportion of patients developed hypoalbuminemia after aneurysmal SAH. Patients with poor clinical presentation had significantly lower admission and postoperative albumin values than those with good clinical presentation. Comparison of patients with a favorable outcome and those with an unfavorable outcome revealed a significant difference in postoperative albumin values. In the patients with severe clinical presentation, postoperative albumin levels lower than 3.5 g/dL were associated with an unfavorable outcome. As a result of our analysis, albumin is an important prognostic factor in aneurysmal SAH. Therefore, active albumin replacement therapy might improve neurological outcomes as a neuroprotective agent. We therefore suggest that albumin offers great promise in the therapy of complications of SAH and we propose that it may now be appropriate to consider the initiation of early-phase clinical trials in patients with aneurymal SAH.