Background: anti-vascular endothelial growth factor (anti-VEGF) has been suggested for the treatment of macular edema. In this study we are assessing the efficacy of one type of anti-vascular endothelial growth factor which is Bevacizumab (Avastin) in the reduction of macular thickness. Patients and Methods: from the period of February 2012 to February 2015, we have gathered the data of 54 patients (39=males, 15 =females) suffering from macular edema who received variable number of intraocular injections of Bevacizumab to be included in a retrospective study. One eye from each patient was chosen randomly and then we observe their follow-up Optical Coherence Tomography (OCT) for any changes in the thickness of the macula. Results: after receiving a single Bevacizumab injection, 16 patients (29.6%) did not show any improvement while 22 (40.7%) patients show an improvement that was less than 50 microns of reduction in magnitude, 5 patients (9.2%) showed an improvement that was greater than 50 microns in reduction of macular thickness and the remaining 11 patients (20.3%) had a reduction of macular thickness that was greater than 100 microns. Conclusion: despite being used originally for metastatic colon cancer, Bevacizumab (Avastin) can be used in the treatment of diabetic macular edema.