Passive immunoprophylaxis after liver transplantation in HBsAg-positive patients. 110 HBsAg-positive patients underwent orthotopic liver transplantation and received long-term anti-hepatitis B virus (HBV) passive immunoprophylaxis with anti-HBs immunoglobulin. During a mean follow-up period of 20 months, all patients became HBsAg negative after transplantation but circulating HBsAg reappeared in 25 (22.7%). Overall 1-year survival was 83.6% and overall 2 year actuarial recurrence of HBsAg was 29% (59% after posthepatitis B cirrhosis, 13% after posthepatitis B-delta cirrhosis, and 0% after fulminant hepatitis B). Patients with HBV cirrhosis who were HBV-DNA positive had a much greater risk of HBsAg recurrence than patients who were HBV-DNA negative (96% vs 29% at 2 years). Reappearance of HBsAg was associated with evidence of HBV replication and abnormal histological findings in the graft. Long-term passive anti-HBV immunoprophylaxis significantly reduced HBV reinfection and improved survival in patients without evidence of active HBV replication before orthotopic liver transplantation. 