OBJECTIVE: Aneurysmal rebleeding is a major cause of death and disability. The aim of this study is to investigate the incidence of rebleeding, and the factors related with patient's outcome. METHODS: During a period of 12 years, from September 1995 to August 2007, 492 consecutive patients with aneurysmal subarachnoid hemorrhage (SAH) underwent surgery at our institution. We reviewed the patient's clinical records, radiologic findings, and possible factors inducing rebleeding. Also, we statistically analyzed various factors between favorable outcome group (FG) and unfavorable outcome group (UG) in the rebleeding patients. RESULTS: Rebleeding occurred in 38 (7.7%) of 492 patients. Male gender, location of aneurysm (anterior communicating artery) were statistically significant between rebleeding group and non-rebleeding group (p = 0.01 and p = 0.04, respectively). Rebleeding occurred in 26 patients (74.3%) within 2 hours from initial attack. There were no statistically significant factors between FG and UG. However, time interval between initial SAH to rebleeding was shorter in the UG compared to FG (FG = 28.71 hrs, UG = 2.9 hrs). CONCLUSION: Rebleeding occurs more frequently in the earlier period after initial SAH. Thus, careful management in the earlier period after SAH and early obliteration of aneurysm will be necessary.