Retinopathy is a primary morbidity occurring in retinopathy diabetic patients and may cause blindness. The failure of laser treatment to stop the new neovascularization may result in severe vision damage. Vitrectomy is indicated in severe vision patients to improve their vision. The aims of the study were to discuss vitrectomy in diabetic retinopathy patients, refresh the knowledge on how and when Vitrectomy should be performed, and to understand the side effect in order to obtain optimal vision improvement. The method is literature study. Progressive fibrovascular proliferation in diabetic retinopathy patients may lead to retinal detachment. The detachment of posterior retinal without involvement of fovea can be observed. However, if fovea is involved, vitrectomy is indicated. If adequate Laser fails due to media opacity, cataract surgery may be performed. Laser photocoagulation can be conducted a few days postsurgery. Alternatively, both vitrectomy and endolaser may be recommended along with lensectomy and intraocular lens implantation. Diabetic Retinopathy Vitrectomy Study(DRVS) concluded:1) in severe vitreous bleeding eyes, early vitrectomy may result in improved vision despite the high risk of vision loss which needs to be considered.2)In the IDDM patients, especially those with severe vitreous bleeding, early vitrectomy is more beneficial and may have a good result. Postoperative complications may occur including retinal detachment, vitreous bleeding, rubeosis iridis, and other types of complications, which require further considerations for optimal result.The prognosis after vitrectomy depends on the macular function. Surgery for vitreous bleeding without macula detachment generally brings a good result.