Purpose of reviewCytomegalovirus is a major viral pathogen complicating organ transplantation. Recent advantages have been achieved through the development of new diagnostic technologies and use of antivirals. Cytomegalovirus-associated indirect effects, such as risk of rejection, transplant vasculopathy, and other infections, have been investigated.Recent findingsQuantitative molecular methods to monitor viral load, especially the new real-time polymerase chain reaction techniques, are commonly used to guide treatment of cytomegalovirus infections and preemptive therapy. Intravenous ganciclovir is the drug of choice for treatment of symptomatic infections, and its oral form is successfully used in prophylactic and preemptive regimens. High-dose acyclovir or its derivative valacyclovir is useful for prophylaxis of cytomegalovirus disease, and valganciclovir, a derivative of ganciclovir, is under clinical investigation. The criteria for cytomegalovirus infection and disease have been updated. Besides enhanced transplant vasculopathy, the indirect effects of cytomegalovirus—association with acute or chronic rejection—are suggestive but not conclusive. Involvement of cytomegalovirus in coronary artery remodeling is associated with the impaired ability of the vessel wall to enlarge in response to intimal increase. Alloresponse is involved in the pathogenesis of cytomegalovirus-enhanced chronic changes; chemokines play a major role in this process, as shown in animal models. Posttransplant recurrence of hepatitis C virus and concurrent activation of human herpesvirus-6 and human herpesvirus-7 are new associations of cytomegalovirus.SummaryAlthough new diagnostic techniques and prophylactic and preemptive therapies have made it easier to control the virus, cytomegalovirus infection remains a significant problem in transplantation. Further clinical investigation is needed to understand the indirect effects of cytomegalovirus.