The treatment of a child with a relapsed state acute leukemia after allogeneic stem cell transplantation (allo-SCT) is a challenge. The authors report about a child with an acute myelogenous leukemia (AML), which relapsed after allo-SCT despite immunological intervention. It was further treated with a second line chemotherapy followed by an infusion of stem cells and donor lymphocytes. Because of an immense risk for a further relapse, an immunological maintenance therapy was also performed, consisting of repetitive infusions of low doses of donor lymphocytes combined with low-dose chemotherapy. Presently, the child is in continuous complete remission and has a good quality of life.