Purpose To evaluate by multifocal electroretinography (MFERG) and optical coherence tomography (OCT) the effectiveness of intravitreal use of bevacizumab (Avastin) in the treatment of macular edema due to central retinal vein occlusion (CRVO). Methods A total of 10 eyes of 10 patients (six males and four females) with macular edema due to CRVO were studied before and after intravitreal use of bevacizumab with MFERG and OCT. The post treatment follow-up was 3 months. Examination included measurement of best-corrected visual acuity (BCVA) for distance, measurement of intraocular pressure (IOP), fluorescein angiography, foveal-retinal thickness measurement by OCT, and MFERG recordings before treatment and 1 and 3 months after treatment. Results Before treatment, OCT shows an increase of the retinal thickness of the fovea. About 1 and 3 months after treatment the foveal thickness decreased to a significant level. The electrical responses in the fovea and parafovea of the MFERG recording depicted a significant improvement at 1 and 3 months after the injection. No patient manifested IOP increase. Conclusion The intravitreal use of bevacizumab may provide anatomical and functional amelioration of the macula in patients with macular edema due to CRVO. However, further study is needed in order to assess the treatment’s long-term efficacy.