• Pars plana vitrectomies were performed on 43 eyes with traction macular detachment secondary to proliferative diabetic retinopathy. Anatomic success, as judged by reattachment of the macula, occurred in 28 (65%) eyes. Improved visual acuity occurred in 11 (26%) eyes. Severe complications occurring after vitrectomy included moderate to severe rubeosis iridis diabetica (28%), neovascular glaucoma (16%), vitreous hemorrhage (49%), and phthisis bulbi (14%). Eyes that received scatter photocoagulation therapy at some time prior to macular detachment had a substantially lower incidence of successful postoperative reattachment of the macula than eyes never treated with photocoagulation.