This paper presents the clinical features, investigation results and response to treatment of four cases of primary optic neuropathy in Behçet's syndrome, with a comprehensive literature search for all other published cases. A total of 20 cases has been identified; the clinical syndrome is a unilateral or bilateral optic neuropathy of inflammatory type in which pain arises in 20 % and optic disc swelling seen in 45 % of cases. The condition was relapsing in four cases, and a progressive optic neuropathy was seen in one case. All but the progressive case responded to steroids with or without additional immunosuppression. The nadir visual acuity was the only determinant of visual outcome. 67 % of cases reported a return to normal acuity following treatment.