We used cyclosporin A (CA) to treat 14 patients (25 eyes) with Behçet's disease characterized by severe retinal vasculitis and active intraocular inflammation. All of the patients had been treated previously with corticosteroids, colchicine, and immunosuppressives, without satisfactory results. The patients were given an initial oral dose of 5 mg/kg/day. All medication was tapered and eventually completely stopped after 12 months. The number and severity of ocular attacks (anterior and/or posterior uveitis with vitreous haze) were significantly reduced below pretreatment levels during therapy (Kolmogorov Smirnov two-pair test: P < .05). Visual acuity improved in 32% and remained unchanged in 44%. No ocular attacks recurred in 11 eyes; they recurred 1 time in 8 eyes; 2 times in 3 eyes; and 3 times in 3 eyes during CA therapy. There were no significant changes in the level of retinal vasculitis. In two cases with vaso-obstructive changes, treatment with CA was not effective and laser photocoagulation was performed. Based on our study, we recommend that an initial dose of 5 mg/kg/day CA be used in the systemic medical treatment of ocular Behçet's disease. The CA can be continued at this low dosage for an unspecified time. If intraocular inflammation does not totally resolve at this dosage or the inflammatory process recurs, combining the CA with low doses of a steroid should be considered.