Dominant symptoms in 24 patients with neurological manifestations of Behçet's disease were meningo-encephalitis (13 cases), febrile meningeal syndrome (3 cases), intracranial hypertension (6 cases), polyneuritis of the lower limbs (1 case), and isolated retrobulbar ocular neuritis (1 case). Several classical notions concerning the "Neuro-Behçet" meningo-encephalitis were confirmed: the frequency of central motor lesions (33 p. cent), cerebrospinal fluid alterations (anomalies in 100 p. 100 of cases in the initial stage), and the often unfavorable course (40 p. cent). An unusual finding in this series was the frequency of cerebral veins thrombosis (4 certain and 2 probable). These could be differentiated from meningo-encephalitis by their symptomatology, predominantly that of intracranial hypertension, and by their course: often the first disorder to appear in the course of Behçet's disease, they followed a favorable neurological course but were constantly complicated by other vascular manifestations, usually phlebitis. It is suggested that a long-term anticoagulant treatment should be associated with corticoid therapy in these forms.