Objective: To report our outcomes with the repair of spontaneous cerebrospinal fluid (CSF) leaks and to demonstrate how management of underlying intracranial hypertension improves outcomes. Study Design: Retrospective review of spontaneous CSF leaks treated at the University of Pennsylvania Health System from 1996 to 2006. Data collected included demographics, nature of presentation, body mass index (BMI), site of skull base defect, surgical approach, intracranial pressure, and clinical follow-up. Results: Fifty-six patients underwent repair of spontaneous CSF leaks. Eighty-two percent (46 of 56) were obese (average BMI 36.2 kg/m2). Nine patients had multiple CSF leaks. Fifty-four patients (96%) had associated encephaloceles. Fifty-three CSF leaks (95%) were successfully repaired at first attempt (34 months of follow-up). Intracranial pressures averaged 27 cm H2O. Patients were treated with acetazolamide or, in severe cases, with a ventriculoperitoneal shunt. Conclusions: Spontaneous CSF leaks have the highest recurrence rate of any etiology. With treatment of underlying intracranial hypertension coupled with endoscopic repair, the success rate (95%) approaches that of other etiologies of CSF leaks. © 2008 American Academy of Otolaryngology-Head and Neck Surgery Foundation.