A retrospective study of 150 patients who underwent closed vitrectomy through the pars plana evaluated the incidence and character of postoperative corneal complications. Corneal changes developed in 43% of patients. Thirty patients had significant corneal complications, half of which resolved with treatment. Fourteen patients had complications that necessitated corneal surgery or resulted in loss of useful vision. Diabetic patients were at greatest risk for corneal problems, particularly postoperative epithelial defects. Intraoperative lensectomy was the only other factor that increased the corneal complication rate. The importance of early recognition and therapy for corneal changes after vitrectomy becomes apparent.