Vitreous surgery was used to treat 130 consecutive cases with epiretinal membranes causing macular pucker. The membrane: (1) occurred after otherwise successful retinal reattachment surgery in 78 eyes (60%), (2) was idiopathic in 28 eyes (22%), (3) was associated with other ocular disorders in 20 eyes (15%), and (4) in four eyes may have been developmental. The abnormal tissue was successfully removed in 128 of 130 eyes, and vision improved at least two lines on the Snellen chart in 108 eyes (83%). Postoperative visual acuity was 20/20 in five eyes (4%), 20/25 to 20/40 in 41 eyes (31.5%), 20/50 to 20/100 in 64 eyes (49%), 20/200 in 15 eyes (11.5%), and 20/400 in five eyes (4%). Complications included one case of sterile endophthalmitis and one case of infective endophthalmitis (Staphylococcus epidermidis). Peripheral retinal tears occurred in six eyes (5%). No posterior retinal breaks occurred in this series. Later retinal detachment occurred in eight eyes (6%) requiring further retinal surgery. Progressive postoperative nuclear sclerotic lens changes occurred in 31 (34%) of 90 phakic eyes. Sizable amounts of epiretinal tissue recurred postoperatively in four eyes (3%).