Bevacizumab is an anti VEGF antibody which has been used to induce regression of ocular neovascularization. Its intraocular injection has been increasingly used for treatment of choroidal neovascularization (CNV) associated with age related macular degeneration (AMD) with fairly good success.Also it has been shown to be effective for treatment of PDR complicated with vitreous hemorrhage and iris neovascularization. We hypothesized that if anti-angiogenic agents, such as bevacizumab are injected into the vitreous cavity before vitrectomy in cases of PDR; there may be partial regression of neovascularization resulting in less intraoperative (and postoperative) hemorrhage. This can make the operation easier and shorter and lessen the need for intraocular cautery..