While orthotopic liver transplantation (OLT) has become the treatment of choice for most irreversible end-stage liver diseases, its role in patients with hepatitis B (HBV) infection is controversial. A high risk of reinfection of the transplanted graft, associated with significant morbidity and mortality, has been reported. Although passive and active immunization can delay reappearance of the virus in the allograft, there is not yet an effective therapy for recurrent HBV infection in liver transplant recipients. Between October 1985 and March 25, 1991, 28 OLT in 25 patients with acute and chronic HBV infections were performed. Twelve of the patients were HBV DNA-negative, six were HBV DNA-positive, and seven were not tested prior to transplantation. Only the 19 patients surviving more than 100 days after transplantation were considered to have sufficient duration of follow-up (mean 734 days; range 500-1545) to include in analysis of recurrence. Five (26%) were free of recurrent disease at the time of last follow-up (mean 1031 days, range 526 to 1770 days. Recurrent HBV in the allograft, as defined by positive immunoperoxidase stains of biopsy sections for viral antigens, was detected in 74% (13 male, 1 female; 7 Asian, 7 white) at a mean of 134 days posttransplantation. Histological changes of viral hepatitis, first appearing an average of 157 days (range 95-326) posttransplantation, were evident in 13 of 14 with positive immunostaining. Twelve of the 14 patients were treated, on an open trial basis, with intravenous and oral prostaglandin E (PGE) because of deteriorating clinical condition. Eleven of the twelve responded to PGE with an initial drop in serum transaminases, improvement in coagulopathy and resolution of encephalopathy. One patient failed to respond and died of a myocardial infarction within 9 days of institution of therapy. Three of the eleven patients with an initial response relapsed and died in liver failure as a direct result of recurrent HBV after 13, 16, and 37 days of treatment in association with generalized sepsis. Eight of the 12 patients (67%) had a sustained favorable response to PGE therapy (mean follow-up 737 days, range 403-1545). All patients with a sustained response had accompanying improvement in histology and reduction in viral antigen staining in hepatocytes. Treatment with PGE appeared to be of benefit in recurrent HBV infection of the transplanted liver with an initial response rate of 92% and a sustained response rate of 67%.