Introduction: Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus and the leading cause of blindness in young adults. Prior to anti-vascular endothelial growth factor (anti-VEGF) agents, the treatment of DR was based on control of systemic factors and laser photocoagulation. Over the past decade, the use of anti-VEGF agents has revolutionized the treatment of DR, including diabetic macular edema (DME).Areas covered: Ranibizumab has been proven to be effective for the treatment of DME in large clinical trials, while patients in these studies have been assessed in terms of DR severity change. In this review, evidence from randomized trials regarding the use of ranibizumab for DR treatment is presented.Expert opinion: A comprehensive presentation of randomized clinical trials evaluating ranibizumab for DR indicates that it is effective and safe, offering improvement of DR severity in both non-proliferative and proliferative forms. However, there is no general consensus regarding the exact treatment regimen in patients with DR, while the effect of ranibizumab on the progression of retinal ischemia remains unclear.