Causes of failure after repeat vitreoretinal surgery for recurrent proliferative vitreoretinopathy. During the last two years, we performed vitreoretinal surgery on 37 eyes with retinal detachments and recurrent severe proliferative vitreoretinopathy in 37 patients who had had previous failed scleral buckling and vitreous surgery for proliferative vitreoretinopathy. Anterior proliferative vitreoretinopathy was present in 32 of 37 eyes (86%); posterior proliferative vitreoretinopathy of fixed retinal folds in four quadrants of narrow or closed funnel shape occurred in 23 of 37 eyes (62%); and subretinal proliferation was noted in 16 of 37 eyes (43%). The retinas in 12 eyes (32%) redetached from new or recurrent anterior proliferative vitreoretinopathy in nine eyes, reopening of pre-existing retinal breaks in two eyes, or recurrent posterior periretinal proliferation in one eye. With additional vitreoretinal procedures in six eyes and after a mean follow-up period of 11 months, 27 of 37 retinas (73%) were totally reattached, and an additional five eyes (13%) had retinal reattachment posterior to the scleral buckle. Of the 32 patients with posterior retinal reattachment, final visual acuity of 5/200 or better was attained in 19 eyes (59%). 