Transplantation of livers from anti-hepatitis B core antibody (anti-HBc)-positive donors into anti-HBc-negative recipients is associated with a high rate of viral transmission. We report a prophylaxis regimen based on virologic evaluation of the donor. Liver and serum from hepatitis B surface antigen (HBsAg)-negative, anti-HBc-positive donors were evaluated by polymerase chain reaction (PCR) for hepatitis B virus (HBV) DNA. All anti-HBc-negative recipients were given a single dose of hepatitis B immunoglobulin (HBIG) during the anhepatic phase of transplantation and were placed on maintenance lamivudine monotherapy. Recipients were followed up longitudinally monitoring intrahepatic HBV DNA as well as serologic HBsAg and HBV DNA by PCR. Between January 1999 and August 2001, 14 anti-HBc-negative recipients received liver transplants from anti-HBc-positive donors. All donor serum was negative for HBV DNA. In total, nine of 14 (64%) livers had detectable HBV DNA; 1 patient was initially PCR-negative and low levels of HBV DNA were detected in a posttransplantation liver biopsy. Mean follow-up was 33 months (range, 22 to 51), and patient and graft survival were each 93%. One case of de novo hepatitis B occurred in a patient noncompliant with lamivudine, although all other serial serum HBsAg assay results were negative. Single-dose HBIG followed by maintenance lamivudine monotherapy prevented de novo hepatitis B in compliant patients. For the cohort of compliant patients that were initially HBV DNA-positive, 7 of 8 (88%) now have undetectable virus in the hepatic allograft by PCR analysis. Nevertheless, there is no evidence to suggest that viral eradication occurs. Accordingly, all patients are maintained on continued lamivudine prophylaxis.