This is a prospective descriptive study for evaluation of male erectile function in End Stage Renal Disease (ESRD) patients before and after KT. 15 male ESRD patients between 16-62 years old (median 35.26 years) evaluated for biochemical (LTH, Testosterone, Creatinine, FBS, cholesterol, triglyceride) and also relation between erectile function and age, hemodialysis period before KT, smoking, history of trauma, alcohol, DM, hypertension and psychological questionnaire according to EDIS & IIEF-5 test and at last Rigi-scan all before and after KT. 1) Testosteron (p=O.OO1) and prolactin -(p=O.OO5) serum levels changed significantly after KT. 2) FBS was 123+-55.34 before and decreased to 86+22.79 after KT(p=O.O35). 3) Serum cholesterol changed significantly (p=O.O13) but serum triglyceride not (p=O.668). 4) Blood urea and creatinine decreased significantly (p=O.OO3 & p=O.OOO). 5) Resuts of IIEF-5:11 cases (73.33%) had better,2 cases (13.33%), had no change and 2 cases (13.33%) had worse IIEF-5 test after KT. 6) Rigi-scan (NPT test) improved in 11 (73.33), no change in 3 (2O%) and worsened in1 case (6.3%). 7) Results of EDIS; The numbers of mild, moderate and severe ED cases decreased and normal cases had increased.Successful KT will improve erectile function nearly in most cases of ESRD patients with ED.