Purpose: The aim of this study is to evaluate electrophysiological changes before and after pars plana vitrectomy for diabetic vitreous hemorrhage Subject & Method: This study included 30 eyes of 30 patients with diabetic vitreous hemorrhage undergoing pars plana vitrectomy. All subjects underwent complete ophthalmological examination, Ultrasonography, Visual evoked potential, Electroretinography before and after vitrectomy (at 1 week &3 months) Results: There was a statistically significant improvement in the Uncorrected Visual Acuity (UCVA) and the Best Corrected Visual Acuity (BCVA) along the study period (p <0.001). There was statistically significant improvement in the mean latency and mean amplitude of Flash VEP There was a statistically significant increase in the mean amplitude of all ERG parameters at 3 months postoperative. Conclusion: Electrophysiological test is an important tool in detection improvement of retinal function after vitrectomy