A 37-year-old male patient with adult T cell leukaemia (ATL) began receiving chemotherapy in March 1992. He achieved complete remission in May 1992, but developed acute myeloid leukaemia (AML, FAB subtype M2) with t(9;11)(p22;q23) in May 1993. The presence of chromosome 11 abnormality at band 11q23 in this patient suggests that the AML was related to the chemotherapy with etoposide for ATL. Furthermore, the combination of etoposide with two cytostatic drugs, cyclophosphamide and carboplatin, possibly induced the leukaemia early (14 months) after the start of chemotherapy. To our knowledge, this is the first report of therapy-related AML after chemotherapy for ATL.