Chronic hepatitis B virus infection is still a major cause of liver disease for which no definite therapy is available as yet. We report a case of HBsAg carrier who was treated for acute myelocytic leukemia by bone marrow transplantation from a hepatitis B virus immune donor. Following bone marrow transplantation, immune reconstitution of the recipient's bone marrow resulted in clearance of the circulating HBsAg. Therefore, this report provides an evidence that adoptive transfer of specific immunity against hepatitis B virus through allogenic bone marrow transplantation may lead to the clearance of the persistent hepatitis B virus infection. Allogenic bone marrow transplantation is associated with high morbidity and mortality and hence has not been suggested as a therapeutic mean for the clearance of the hepatitis B virus. However, although not practical at this time, selective transfer of specific cell-mediated immunity to hepatitis B virus and possibly also to other life threatening infectious agents can be used as a new therapeutic modality.