Cytomegalovirus (CMV) infection and CMV disease remain important issues in renal transplantation. Incidence depends on individual patient risk. There are different possible strategies for CMV prophylaxis. In our center CMV prevention includes prophylaxis with low-dose valganciclovir for all high-risk recipients; for the remaining patients, valganciclovir is only prescribed when there is evidence of CMV replication. All recipients are monitored for viral replication. We evaluated the results of this preventive strategy in all 135 patients who underwent transplantation between 2006 and 2007 in our center. Average follow-up time was 16 months (6-30 months). Fifty-one recipients (38%) received CMV prophylaxis. The median duration of prophylaxis was 84 days. In 37% of the recipients (50 patients) CMV antigenemia became positive, and were given therapeutic doses of valganciclovir. Of these patients, 32% were high-risk recipients undergoing prophylaxis. CMV infection rate was 40% in the group not receiving prophylaxis. No association was observed between CMV infection and prophylaxis duration. However, 50% of patients who suspended prophylaxis before completion of the first 3 months became infected. There were 3 cases of CMV disease (2.2%). Leukopenia was seen in 34% of patients receiving prophylaxis. Valganciclovir prophylaxis for high-risk patients seems to be effective and safe among subjects who complete the full duration of treatment. Despite CMV-positive antigenemia in 40% of patients not undergoing prophylaxis, pre-emptive therapy with valganciclovir was effective to prevent CMV disease, but close monitoring is essential for disease prevention.