Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus-6 (HHV-6) cause symptomatic diseases in liver transplant recipients. The loads of these viruses, the associations between viral DNAemia, serologic status, and acute rejection reactions were investigated in a group of 17 juvenile and 17 adult recipients of living donor liver transplantation (LDLT) for a median of 8 weeks posttransplantation. At least 1 plasma sample from 15/34 (44.1%) patients was positive for CMV DNA. For most of the CMV-positive patients, the CMV DNA appeared in the second week of LDLT, and disappeared by the eighth week. A minimum of 200 EBV DNA copies/mug peripheral blood mononuclear cell DNA (defined as positive for EBV) was detected in 5/34 (14.7%) patients, and the number of EBV-positive children was significantly greater than the number of EBV-positive adults. In most of the EBV-positive patients, the EBV loads increased after 4 weeks posttransplantation. Plasma HHV-6 was detected in 7/34 (20.6%) patients. HHV-6 DNA appeared for a short period from the second week of LDLT. In addition, 8 of the 19 virus-positive recipients carried 2 viruses, with the combination of CMV and HHV-6 being the most frequent. Serologic status seemed to be an important factor for all 3 viral infections. The rate of acute cellular rejection was not significantly higher in the CMV-, EBV-, or HHV-6-positive groups. Simultaneous monitoring for 3 herpesviruses revealed the impact of these viruses on LDLT recipients.