Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are common complications after orthotopic liver transplantation (OLT), but the liver pathology and clinical outcomes of HBV infection with HCV coinfection have not been thoroughly examined. In this study, we used the polymerase chain reaction (PCR) to detect HBV and HCV in pre- and post-OLT sera of 38 patients and correlated the findings with clinical outcome and liver pathology. Of 13 patients who were HBV and HCV negative before OLT, 9 acquired HBV infection, and 4 developed acquired HBV and HCV coinfections after OLT. Persistent HBV infections were present in 10 patients. Three patients with pre-OLT HBV infections developed persistent HBV and acquired HCV coinfections after OLT; 5 with pre-OLT HCV infections developed acquired HBV and persistent HCV coinfections after OLT, and 7 had persistent HBV and HCV coinfections before and after OLT. Portal/periportal inflammation was the same in all groups; however, lobular inflammation and fibrosis were more severe in patients with persistent HBV infections and in those with acquired HBV and HCV coinfections. Two major histopathological patterns were present in patients with HBV and HCV coinfections, one with predominant features of HCV infection, and the other with those of HBV infection. Patients with post-OLT HBV and HCV coinfections had survival rates similar to those with acquired HBV infection, whereas patients with persistent HBV infections experienced more allograft loss caused by chronic hepatitis or fibrosing cytolytic hepatitis, and had a more dire clinical outcome than the others. Although the limited numbers reported in this study prevent a definitive conclusion, our data suggest that in patients with HBV and HCV coinfections, the presence of HCV may improve the clinical outcome as compared with the expected outcome of persistent HBV infection alone.