Re-activation of porcine cytomegalovirus (PCMV) in the xenograft has been reported in pig-to-baboon models of xenotransplantation and is associated with invasive disease and consumptive coagulopathy. If xenotransplantation of porcine organs into human recipients is to proceed, donor organs will have to be free from a wide range of infectious agents including PCMV. However, it is prudent to characterize the antiviral susceptibility of this virus. We therefore investigated the effect of selected antiviral agents, currently licensed for the treatment of human herpesvirus infections, on PCMV replication.Antiviral susceptibility was determined using real-time PCR and indirect immunofluorescence measurements in a porcine fallopian tube cell line infected with PCMV.PCMV replication was significantly inhibited by ganciclovir and cidofovir (both EC(50) 25 mg/L).These results show that, if it proves necessary, ganciclovir and cidofovir should be considered as first-line drugs to treat PCMV infections in xenograft recipients.