Abstract    INTRODUCTION: Post-transplant diabetes mellitus (PTDM) contributes to the risk for cardiovascular disease and infection, reducing graft and patient survival. This study was conducted to identify incidence and risk factors for development of PTDM.    METHODS: We studied 50 non-diabetic adult dialyzed patients awaiting renal transplantation prospectively. Oral glucose tolerance test () was performed pre- and post-transplantation. The relation of age, weight (BMI), dialysis modality, family history of diabetes, duration of dialysis was assessed with occurring PTDM.    RESULTS: Based on 1, 13 patients had unknown Diabetes Mellitus; however after transplantation only 9 of them had same results. Based on 2 6(16.22%) patients had actually PTDM. Age of patients with PTDM were significantly higher than those with normal test (43± 17 versus 31± 11 year old) (P<0.05). There was significant relation between duration of dialysis with PTDM (P<0.05), as normal was seen in 85.2% patients that dialyzed less than 1 year. There was no significant relation among dialysis modality and family history of diabetes and BMI with PTDM (P>0.05).    CONCLUSION: Risk factors for diabetes in our study were age and duration of dialysis before transplantation. Then identifying them might allow modification of post transplant immunosuppressant with nondibetogenic agents in high risk patients.      Keywords: post-transplant diabetes mellitus, oral glucose tolerance test, renal transplantation.