Treatment of acute leukemia relapse following an allogeneic transplantation is a challenge. We reinduced three pediatric patients with acute myeloid leukemia (AML) relapsing after a marrow transplantation from a sibling donor into remission with chemotherapy and used donor lymphocyte infusions (DLIs) as consolidation. In two of the cases, the allogeneic recognition was enhanced through the use of interferon in the absence of clinical graft vs. host disease (GVHD). Subsequently, all the three developed (acute grade III-IV or chronic extensive) GVHD and remain in remission with a good quality of life 19, 15 and 14 months post-relapse. We consider an active approach in the treatment of pediatric AML relapsing post-transplant justified.