Cytomegalovirus (CMV) disease is one of the leading causes of morbidity and mortality after kidney transplantation. Despite the growing number of kidney transplantation in Iran, there is few data available on risk factors of this disease. The aim of this study was to clarify this. We prospectively followed all the kidney recipients in Baqiyatallah Hospital, Tehran, Iran between 2002 and 2005 for the clinical evidences of CMV disease. Suspected patients were entered the study and assessed for the presence of pp65 in leukocytes, which confirms the diagnosis in suspected patients. Demographic data, cause of ESRD, history of graft rejection and past medical history were also assessed in all patients. During this period, 127 patients entered the study, of them, 30 patients were pp65 positive and diagnosed as having CMV disease (male: 21(70%), female: 9 (30%). Mean age at infection was 48.87 ± 15.37 years. Mean duration between transplantation and the diagnosis of CMV disease was 4.59 ± 11.56 months. Patients with CMV disease have significantly higher age at transplantation and a history of diabetes mellitus compared to other patients (p=0.01). This relationship was not seen in gender, educational level, socioeconomic status, history of graft rejection and blood transfusion (p>0.05). Our results showed that the patients with clinical findings similar to CMV disease with diabetes mellitus and older age at transplantation are at higher risk of CMV disease. Prophylaxis considerations, at least in high risk patients, should be emphasized for prevention of this disease.