The standard evaluation of patients with intracranial hypertension frequently does not reveal a discrete pathophysiologic process, leading in these cases to classification of the syndrome as "benign." We present a 35-year-old woman with a recent diagnosis of pseudotumor cerebri who presented with headache, emesis, and blurring of vision. Her symptoms were progressive despite two lumbar punctures that revealed normal cerebrospinal fluid under high pressure. Contrast and noncontrast CT scans were normal; both the cerebrospinal fluid and CT neuroimaging were thus consistent with benign intracranial hypertension. An MRI, however, supported the presence of sagittal sinus thrombosis, a finding which was confirmed by MR venography. Further workup for an underlying cause of sinus thrombosis disclosed symptoms and signs fulfilling the diagnostic criteria for Behcet's disease. Cerebral venous (or sinus) thrombosis should be considered in the differential diagnosis of intracranial hypertension. Behcet's disease, while extremely rare, should be considered as a potential cause of cerebral venous thrombosis. Magnetic resonance venography can serve as a useful diagnostic study in situations where confirmation or exclusion of sinus thrombosis is required.