A patient with macular edema secondary to a branch retinal vein occlusion (BRVO) was treated with intravenous injections of infliximab, an antitumor necrosis factor (TNF)-alpha antibody, for her rheumatoid arthritis (RA). Before the injection, the thickness of the right fovea, determined by optical coherent tomography, was 629 mum and the best-corrected visual acuity (BCVA) was 20/50. After eight injections of infliximab and 10 months after the first injection, her foveal thickness was decreased to 293 mum and the visual acuity improved to 20/20. There was no recurrence of macular edema during the infliximab injections. However, the infliximab injection was stopped because the patient developed pneumonia. Eight months after stopping the infliximab injection, her foveal thickness increased to 494 mum. To treat the RA, her orthopedists began weekly subcutaneous injections of etanercept, a fusion protein of a section of the TNF receptor and immunoglobulin. Five months later, the foveal thickness had decreased to 260 mum, and the visual acuity remained at 20/25(+). Because TNF-alpha is known to break down the blood-retinal barrier, the improvements in our case suggest that TNF-alpha plays a role in the pathogenesis of macular edema in some patients with BRVO.