We postoperatively evaluated the data from 10 patients who underwent pars plana vitrectomy and intravitreal silicone oil injection for complications of proliferative diabetic retinopathy and rubeosis, or for proliferative vitreoretinopathy and rubeosis. There was no change in the zone of iris affected by the rubeosis or in the calibre of rubeotic vessels. Visual acuity improved in two patients and stayed the same in eight. Retinas were completely attached in 50% and partially attached in 30% of the patients on the last follow-up visit. The use of silicone oil in these patients caused no untoward effects in these severely diseased eyes.