Objective: Fever is a common clinical complication in patients with subarachnoid hemorrhage (SAH), and is usually related to prognosis in early stage of diseases. In our study, we try to help improve the outcome of SAH by assessing possible risk factors for fever and investigating the influence of fever on in-hospital mortality. Methods: Fever was defined as axillary temperature above 38.3 degrees C appearing at least two times (not in the same day). One hundred and fifty-five patients with SAH were divided into febrile group and a febrile group. The following data were documented: patient demographics, clinical grade on admission Glasgow Coma Scale score, Hunt-Hess grade), conscious state on admission, presence of seizure, imaging assessment, admission glucose levels and plasma electrolytes levels. Univariate analysis and multivariate logistic regression analysis were used to determine factors associated with fever or in-hospital mortality. Results: Forty-one percent of patients with SAH developed fever. As determined by univariate analysis, older age, history of hypertension, Glasgow Coma Scale score, Hunt-Hess grade, Fisher CT grade, conscious state on admission, presence of intraventricular hemorrhage (IVH), admission glucose levels and plasma electrolytes levels were factors for fever. Multivariate analysis indicated that three factors independently predicted the occurrence of fever: poor Hunt-Hess grade (OR 5.37, 95% Cl 1.56-18.44), presence of IVH. (OR 5.18, 95% Cl 1.43-18.85) and older age (OR 1.06, 95% Cl 1.02-1.09). In-hospital mortality after SAH was associated with fever (OR 17.36, 95% C14.47-67.35), consciousness disorders on admission (OR 5.89, 95% Cl 1.16-29.89) and older age (OR 1.07, 95% CI 1.00-1.13). Conclusions: Poor Hunt-Hess grade, presence of IVH and older age are independent predictors of fever in SAH. Fever is closely related to increased in-hospital mortality after SAH.