Diabetic macular edema may occur or worsen as a consequence of vitreomacular traction in some eyes. The precise role of the posterior hyaloid in the pathogenesis of diabetic maculopathy remains unclear. The determination of which eyes might benefit from vitrectomy is the most challenging aspect in the treatment of this condition. Fluorescein angiography, B-scan untrasonography, and optical coherence tomography may be helpful in this regard. Most often, vitreous surgery is performed when diabetic macular edema persists despite multiple laser treatments. All reports published to date regarding vitrectomy for diabetic macular edema are uncontrolled and nonrandomized patient series. Visual improvement after vitrectomy is related to the duration of edema, as well as the extent of intraretinal lipid and vascular nonperfusion.