Autosomal-dominant polycystic kidney disease (ADPKD), a common hereditary disease, is characterized by the progressive development and enlargement of multiple cysts in both kidneys, and typically resulting in end stage renal disease (ESRD) by the fifth decade of life. Post-transplant diabetes mellitus (PTDM), a common complication after transplantation with an incidence rate of 2.5-20%, is associated with poor graft and patient survival. In few studies, PTDM has been more frequent in ADPKD transplanted patients. In the present study, we investigated whether there is an association of PTDM with ADPKD in our patients. In this prospective study, 140 nondiabetic and nonsmoker successfully transplanted patients (27 ADPKD and 113 nonADPKD patients) were enrolled during three years. Both groups were matched for age, sex, body mass index (BMI), duration of renal replacement therapy before transplantation and also immunosuppressive protocols after transplant. We applied the definition of post-transplant diabetes mellitus presented by Canadian Diabetes Association as Clinical Practice Guidelines for the Management of Diabetes Mellitus in 2002. These patients were evaluated for 12 months. The incidence rate of post-transplant diabeted mellitus was 11.1% In ADPKD transplanted patients and 13.1% in nonADPKD group without any statistically significant difference (P>0.05). The development of PTDM in ADPKD group was not related to sex, age, hypertension, duration of renal replacement therapy before transplantation, BMI and serum creatinine levels (P>0.05). Post-transplant diabetes mellitus appears not to be associated with autosomal-dominant polycystic kidney disease as an etiology of end stage renal disease.