Purpose: To evaluate intravitreal Bevacizumab (IVB) in treatment of diabetic macular edema (DME) using Multifocal Electroretinogram (Mf-ERG). Methods: Twenty eyes of sixteen patients with diffuse and/or focal DME without macular ischemia received primary IVB (1.25 mg /0.1 ml). Multifocal electroretinography was done as baseline, 1 week, 2 weeks and 3 weeks post injection. Results: Mean visual acuity improved from (0.37±0.23) to (0.42±0.30), 25% of patients reported near vision improvement. Central foveal thickness improved significantly from (375.80±14.48 micrometer (μm)) to (225.0±30.08 μm) and parafoveal and perifoveal thickness improved from (317.00±36.2 μm) to (282.80±27.97 μm). At the end of the 3rd week, P wave amplitude improved from (34.64±9.62 nanovolt per square degree (nV/deg2)) to (44.54±8.32 nV/deg2), N wave amplitude improved from (0.135±0.060 nV/deg2) to (0.299±0.160 nV/deg2). Conclusion: Intravitreal Bevacizumab resulted in macular function improvement in the study patients with DME, postoperative improvement in visual acuity and decreased retinal thickness confirmed by improvement of P wave and N wave in Mf-ERG.