['Aneurysmal subarachnoid hemorrhage (SAH) is the most devastating form of hemorrhagic stroke. Primary predictors of mortality are based on initial clinical presentation. Initial serum lactic acid levels have been shown to predict mortality and disease severity. Initial serum lactate may be an objective predictor or mortality.', 'Retrospective review of aneurysmal SAH in a large academic center over a 42-month period. Data collected included demographics, clinical data, serum, and clinical outcomes data. Epidemiologic data were collected at baseline, and patients were followed up through their inpatient stay. We compared data in the group of patients who were deceased (group A) vs survivors (group B).', 'There were a total of 249 patients. Mortality was 21.5%. Mean age was the same for both groups: 57 years (group A) and 55 years (group B). Mean admission serum lactate level was 3.5 ± 2.5 (group A) and 2.2 ± 1.6 (group B; P <. 0001). The range was 0.01 to 14.7. Multivariable analysis controlling for Hunt and Hess grades showed lactic acid levels to be an independent predictor of mortality with a P value of .0018.'] Does admission serum lactate predict mortality in aneurysmal subarachnoid hemorrhage?