AIMS To investigate the clinical course of vitrectomized patients with recurrent diabetic vitreous hemorrhage who were treated by revitrectomy with silicone oil (SO) as a hemostyptic tamponade. PATIENTS AND METHODS Fifteen patients with recurrent vitreous hemorrhage due to proliferative diabetic vitreoretinopathy were included in this retrospective study. All eyes had had at least one vitrectomy prior to use of SO and the retina was completely attached at any time before revitrectomy with SO instillation. Thirteen patients had a blind fellow eye. There were 6 males and 9 females (mean age 62.7 years, range 45-76 years). The mean duration of SO tamponade was 25.8 months (range 9-35 months). The average follow-up period was 30.4 months (range 20-48 months). RESULTS Ten out of 15 eyes (66.6%) improved postoperatively, 9 eyes had a visual acuity of > or = 0.02 at the latest follow-up visit. Secondary glaucoma occurred in 4 eyes, leading to phthisis in 1 eye. All 5 phakic eyes developed a cataract. CONCLUSION A revitrectomy combined with a long-term hemostyptic SO tamponade offers a chance for restoration of useful visual acuity in diabetic eyes with persistent vitreous-hemorrhage that fails to subside after cryocoagulation and vitrectomy without tamponade. Because of possible visual loss from secondary glaucoma related to intraocular SO this treatment should mainly be considered in patients with a blind fellow eye.