AIM: To discuss the role of the triamcinolone acetonide(TA)injection applied in the pars plana vitrectomy(PPV) surgery for proliferate diabetic retinopathy(PDR). METHODS: A prospective controlled clinical study was carried out on 107 eyes from 107 patients with PDR,with 53 patients undergoing TA-assisted PPV and 54 patients in control group undergoing conventional PPV.The retinal break,retinal detachment,vitreous hemorrhage were obeserved and recorded during operation.After treatment, the changes in best-corrected visual acuity (BCVA), intraocular pressure (IOP), macular edema were recorded. RESULTS:Total 104 patients(97.2%) were followed-up for 6-12 months,51 patients(96.2%) in TA-assisted PPV, 53 patients(98.1%) in conventional PPV. The incidence of retinal breaks was significantly lower in TA-assisted PPV than in conventional PPV(P<0.05). Retinal breaks were seen in 3 eyes(5.7%)undergoing TA-assisted PPV compared with 11 eyes (20.4%) undergoing conventional PPV.Retinal detachment,vitreous hemorrhage during operation,and the BCVA,IOP, macular edema after treatment all had no significiant difference. CONCLUSION: TA-assisted PPV offers improved visu- alization, and allows surgeons to excise the epiretinal membrane(ERM) safely and effectively,reduces the incidence of retinal breaks during the surgical management of PVR for PDR. There were no serious adverse events related to the intraoperative use of TA.