Seven patients with hepatitis delta virus (HDV) cirrhosis underwent liver transplantation. In every case the HDV infection was florid but accompanied by an inactive hepatitis B virus (HBV) infection. The patients were given anti-HB surface antigen (HBsAg) serum globulins and HBV vaccine. Two patients cleared the HBsAg and the HDV, and are alive and well 14 and 15 months, respectively, after transplantation. HDV infection recurred in the other five patients: hepatitis developed in three, another died, and the fifth was re-transplanted for causes unrelated to viral hepatitis (reinfection was shown by the presence of HD antigen in the graft). Liver transplantation is feasible in patients with HDV disease but involves a high risk of HDV reinfection that cannot be predicted by the virological pattern of the native HBV infection or prevented by conventional HBV prophylaxis.