Cytomegalovirus (CMV) is considered the most important infectious cause of mortality and morbidity in organ transplant recipients. In this study, we report the impact of CMV infection on the outcomes of renal allograft recipients in our renal transplant population. A retrospective approach was used to analyze data of renal transplant recipients undergoing the procedure at Baqiyatallah Hospital in Tehran, Iran, between 1984 and 2007. Overall, 48 patients (2.1%) were documented as developing CMV disease. 1 patient (2%) died, and 3 (6%) lost their allograft function. Compared to MMF based immunosuppression, azathioprine is less likely to induce CMV disease and also promises better survival (P < .0001 & P<0.001). Being negative for the anti-CMV IgG antibody and receiving an allograft from a positive donor was also associated with CMV disease development and worse patients survival (P = .03 & p<0.0001). This study showed that CMV infection induces unfavorable outcomes in renal allograft recipients, especially when the infection occurs early on in the posttransplant phase. We suggest to closely monitor CMV positive patients and to use less-intensive immunosuppressive treatment. Future prospective studies seem necessary.