Although acute optic neuropathy has been rarely reported in patients with Behçet's disease, a detailed description of its clinical course is lacking. We report in detail the course of acute optic neuropathy in two patients with Behçet's disease. Our experience suggests that it can be bilateral, can affect both eyes simultaneously, and can be recurrent. The severity of the visual loss and its recovery can be very variable even in the same patient. Early recognition of this entity and treatment with high-dose systemic corticosteroids may limit the degree of permanent visual loss. However, the optimal treatment has not been established.