We report a case of donor-derived acute myeloid leukemia (AML) occurring in a 33-year-old man after allogeneic bone marrow transplantation (BMT) for precursor T-cell acute lymphoblastic -leukemia (T-ALL). The cells for BMT were from his human leukocyte antigen (HLA)-matched sister. Fluorescence in-situ hybridization (FISH) analysis showed the AML to be of donor origin (i.e., karyotypically female) with an 11q23 (mixed lineage leukemia (MLL) gene) translocation, while the original T-ALL exhibited a male karyotype with abnormalities of chromosomes 6, 8, and a t(10;14)(q24;q11.2). Subsequent molecular short tandem repeat studies confirmed the AML to be of donor origin. Donor-cell leukemia (DCL) after allogeneic BMT is a rare, yet well-documented, event. Our report presents clinicopathologic information about a case of DCL and a review of the recent literature.