INTRODUCTION. Ranibizumab is an anti-VEGF antibody widely used in DME treatment. MATERIALS AND METHODS. We conducted a literature search using the keywords “diabetes”, “diabetic retinopathy”, “diabetic macular edema”, “pathophysiology”, “VEGF”, “treatment”, “anti-VEGF”, “ranibizumab”, “lucentis” with limitation of English language. The articles published between 2006–2016 years and we reviewed level I and level II studies. RESULTS. Review from several level I and level II intravitreal ranibizumab injection studies suggests that ranibizumab is an anti-VEGF that effectively used in DME treatment. Comparison with other anti-VEGF also suggest that ranibizumab is effective for DME patients for over 2 years treatment. CONCLUSIONS. Ranibizumab monotherapy and/or combination with laser is safe and effective for DME patients for over 2 years treatment.