PURPOSE: To evaluate the effect of intravitreal bevacizumab on the visual and anatomical outcome in eyes with macular edema secondary to branch retinal vein occlusion. METHODS: A retrospective, consecutive case series identified 53 consecutive patients with a branch retinal vein occlusion treated with intravitreal bevacizumab. Clinical variables were analyzed, including best-corrected visual acuity, angiographic characteristics, central foveal thickness, and complications. RESULTS: Fifty-three eyes were identified with a mean initial best-corrected visual acuity of 20/137 and final best-corrected visual acuity of 20/96 (P = 0.05). The mean final line change was +1.6 lines (95% confidence interval, +0.7 to +2.3; +8 letters [95% confidence interval, +3.5 to 11.5]). At final follow-up, 28% gained ≥ 3 lines, whereas a loss of >3 lines was seen in 6% of eyes. The mean initial central foveal thickness of 425 μm decreased to 289 μm (P < 0.001). Mean number of injections was 2.5, and mean follow-up was 9 months. Eyes treated for ≤ 6 months after the onset of branch retinal vein occlusion showed improved functional outcomes (e.g., final best-corrected visual acuity, mean line change) as compared with those treated with >6 months of symptoms (P < 0.01). CONCLUSION: Intravitreal bevacizumab appears to be an effective treatment for macular edema secondary to branch retinal vein occlusion in many subjects. Eyes treated with intravitreal bevacizumab showed a significant reduction in central foveal thickness and improvement in visual acuity. Early treatment with intravitreal bevacizumab resulted in a greater improvement in visual acuity compared with delayed treatment.