Four patients, aged 10 to 44 years, with spontaneous cerebrospinal fluid (CSF) leaks and intracranial hypotension developed intracranial hypertension after treatment of their CSF leaks. The leak was at the spinal level in all patients (thoracic level, 2; lumbar level, 1; and undetermined, 1). One patient responded to an epidural blood patch. Three patients responded to surgery, of whom 2 had not responded to prior epidural blood patches. Treatment resulted in complete resolution of symptoms, including orthostatic headaches and disappearance of magnetic resonance imaging abnormalities. However, all patients later developed steady headaches different from their previous headaches. None had recurrence of magnetic resonance imaging abnormalities or any evidence of occlusion of cerebral venous sinuses. All had increased CSF opening pressures. One had bilateral papilledema, and another had no venous pulsations on examination of fundi. Follow-up was possible in 2 patients. One responded well to treatment with acetazolamide, and the other improved gradually and was asymptomatic within several months.