Silicone oil is now used with increasing frequency to treat cases of complicated retinal detachment (RD). The authors report their results using silicone oil in eyes with RD resulting from proliferative diabetic retinopathy (PDR) or proliferative vitreoretinopathy (PVR). The retina was completely reattached at last examination in 16 (70%) of 23 eyes with PDR and 20 (67%) of 30 eyes with PVR. Final vision of 5/200 or better was obtained in 5 eyes with PDR (22%) and 16 eyes with PVR (53%) (P = 0.0016). Reproliferation of epiretinal membranes occurred in 26% of diabetics and 23% of eyes with PVR. Silicone oil did not cause regression of iris neovascularization. Complications of silicone oil included corneal decompensation, lens opacification, intraocular pressure elevation, and hypotony.