Objective: To investigate the long-term efficacy and safety of low-dose and dose-escalating therapy of interferon alfa-2a in the treatment of Behçet uveitis. Methods: This study included 37 patients with refractory Behçet panuveitis unresponsive to conventional immunosuppressive therapy. Induction interferon alfa-2a therapy was given as a daily dose of 3.0 million IU (MIU) subcutaneously for 14 days. Maintenance dose was achieved with 3.0 MIU 3 times per week given subcutaneously. The dosage was increased sequentially to 4.5, 6.0, and 9.0 MIU 3 times per week if uveitis relapses occurred. Total therapy duration was 24 months. Primary outcome measure was control of uveitis with quiescence during maintenance therapy. Ocular relapses per patient-year before and after initiation of interferon alfa-2a therapy and a corticosteroid-sparing effect were secondary outcomes. We also estimated the rate of remission after discontinuing interferon alfa-2a therapy. Results: During maintenance therapy, interferon alfa-2a controlled uveitis in 35 patients (95%). In 15 patients (41%), a maintenance dosage of 3.0 MIU 3 times per week controlled uveitis without any relapse. The rate of uveitis relapses decreased from 3.52 per patient-year before to 0.75 per patient-year after initiating interferon alfa-2a therapy. Seventeen patients were receiving systemic corticosteroids at the time of initiation of interferon therapy. During the maintenance stage, 9 patients were able to discontinue and 8 to taper systemic corticosteroid therapy. Survival analysis estimated that the rate of remission after discontinuation of interferon alfa-2a therapy was76%by 3 months. The rate of remission remained stable thereafter. Conclusion: A treatment protocol using a low-dose and dose-escalating therapy with interferon alfa-2a was able to control and achieve remission of uveitis in most patients with refractory ocular Behçet disease. ©2011 American Medical Association. All rights reserved.