Severe aplastic anemia (AA) is a life-threatening condition wherein bone marrow transplantation (BMT) is the therapy of choice in a young patient who has a matched sibling donor. Here, we report an 11-year-old boy with severe AA who was referred for BMT late in its course when he had developed acute myeloid leukemia following two courses of immunosuppressive therapy with antithymocyte globulin and cyclosporin. He was then treated with induction therapy using cytosine arabinoside and daunomycin for acute myeloid leukemia, but he succumbed due to infection and refractory leukemia. We discuss the relevance of early referral for BMT in severe AA.