After an eye-wall resection for a choroidal melanoma, a 32-year-old woman had subsequent retinal detachment with proliferative vitreoretinopathy (PVR), and an unsuccessful attempt at repair with retinal tacks. Gross and light-microscopic examination of the globe revealed a total retinal detachment with extensive preretinal and subretinal membranes. The membranes surrounded the tack heads and extended in taut bands to form a tractional detachment of the pars plana. The membranes contained glial and nonglial cells. The glial cells immunolabeled for glial fibrillary acidic protein (GFAP), carbonic anhydrase-C (CA-C), vimentin, and glutamine synthetase (GS), thus suggesting that they were Müller's cells. While the tacks did not seem to cause PVR, in this case they may have provided an anchoring point from which membranes were able to exert traction on the retina and pars plana.