A 48-year-old woman developed painful visual loss in the left eye, meningismus, and painful oral ulcers. Magnetic resonance imaging of the brain with gadolinium demonstrated enhancement of the left optic nerve. Lumbar puncture showed a lymphocytic pleocytosis, and a biopsy specimen of one of the oral ulcerations was consistent with Behçet's disease. Epidemiologic factors and diagnostic criteria for Behçet's disease are discussed.