['Differences in the clinical course of secondary acute myeloid leukemia according to the type of the preceding disorders are not defined. We compared the outcomes of therapy-related acute myeloid leukemia, acute myeloid leukemia following myelodysplastic syndrome and acute myeloiod leukemia following myeloproliferative neoplasm. We also intended to find prognostic factors in secondary acute myeloid leukemia overall.', 'Retrospective medical record review at Seoul National University Hospital was performed. We assessed response to induction chemotherapy and overall survival.', 'Ninety-five secondary acute myeloid leukemia patients (median age of 56.4 years) were analyzed. Twenty-six, 57 and 12 patients had therapy-related leukemia, leukemia following myelodysplastic syndrome and myeloproliferative neoplasm, respectively. For patients receiving induction chemotherapy, complete remission rate was 47.5% and complete remission rate was different according to the type of the preceding disorders (P = 0.004). Compared to therapy-related leukemia (P = 0.027) and leukemia following myelodysplastic syndrome (P = 0.050), leukemia following myeloproliferative neoplasm had shorter overall survival. In secondary leukemia, presence of trisomy 8 had a prognostic impact (P = 0.003) along with cytogenetic risk group (P = 0.016). In multivariate analysis, the type of the preceding disorders (P = 0.026), 5q deletion (P = 0.015) and trisomy 8 (P = 0.040) were independent prognostic factors.'] Is prognosis of secondary acute myeloid leukemia affected by the type of the preceding hematologic disorders and the presence of trisomy 8?