We report four patients with Behçet's disease characterized by initial and predominant neurological signs and symptoms. In three cases, a clinical picture of relapsing meningoencephalitis preceded the appearance of the classical signs of the disease for several months or years; in the fourth case, an acute febrile aseptic meningitis coincided with the development of bipolar aphthosis and uveitis. Disease activity was linked to a blood inflammatory syndrome and neutrophilic leucocytosis. Acute phases were associated with CSF mixed pleocytosis and high protein content. Brain CT scans and MRI were very effective to detect lesions which are mainly located in the brain stem and basal ganglia. High-dose corticosteroids and, in cases of relapses, immunosuppressive drugs were required to treat these severe forms of Behçet's disease.