Two children developed lymphoproliferative processes following marrow transplantation. One of the two lymphoproliferative processes was documented to be Epstein-Barr virus (EBV)-associated. Both children received an extended course of alpha-interferon and gammaglobulin and responded with the disappearance of the lymphoproliferative process. Side effects from the alpha-interferon were minimal. Previous experience with EBV-associated lymphoproliferative processes following marrow transplantation have been usually fatal. This report further substantiates that alpha-interferon has a role in the treatment of EBV-associated lymphoproliferative processes following marrow transplantation.