Abstract: Viral infection is a recognized and potentially serious complication in children following solid organ transplantation. The risks of viral infection are particularly important for infants who may not have completed standard childhood immunizations at the time of transplantation and are therefore at risk for otherwise preventable infections. The general practice of withholding live virus immunization from transplant recipients has been questioned and several small studies have looked at MMR and/or Varivax administration in children following transplantation. This retrospective study analyzes the response to primary MMR and varicella immunization in selected pediatric liver transplant recipients in the largest such study to date. Nineteen of 26 children (73%) developed serologic immunity for measles following MMR (although 18 required multiple doses). Similarly, varicella immunization resulted in seroconversion in 20 of 31 children (64.5%; seven required multiple doses). Only minor adverse effects reported in the general population were observed. Live virus immunization with MMR and Varivax was safe and immunogenic in this selected population of liver transplant recipients.