We report the case of a 47-year-old patient who developed acute myelogenous leukemia (AML) 18 months after receiving high-dose chemotherapy with peripheral blood progenitor cell support (PBPCT) for relapsed low-grade follicular non-Hodgkin's lymphoma (NHL). Cytogenetic analysis of the leukemic cells showed the translocation (9;22)(q34;q11). In three mitoses, an additional Philadelphia chromosome (Ph1) was present. In the literature, Philadelphia chromosome-positive secondary AML has been described only once before in a patient with multiple myeloma.