Objective: To compare the visual and anatomical outcomes of intravitreal ranibizumab (group 1), bevacizumab (group 2), and triamcinolone (group 3) for center-involving diabetic macular edema. Methods: We retrospectively enrolled 275 eyes of 208 consecutive patients. Visual acuity (VA) in Early Treatment Diabetic Retinopathy Study (ETDRS) letters and central macular thickness (CMT) values on optical coherence tomography were extracted. Reported side effects were noted. Results: At 6 months, the mean changes in VA in group 1, group 2, and group 3 were +4.9, +4.3, and +4.6 letters, respectively (p = 0.911). Improvement of CMT at 6 and 24 months was significantly better in group 3 compared to groups 1 and 2 (p = 0.012 and p = 0.001, respectively). At 24 months, the only independent variable affecting the change in VA was initial VA (p = 0.020). Cataract and glaucoma prevalences were higher in group 3 (p = 0.000 and p = 0.001, respectively). Conclusions: Three treatment methods had similar effects with regard to improvement in VA; however, intravitreal triamcinolone provided additional anatomical improvement.