Recurrence of the disease is the major problem in the treatment of acute myeloid leukemia (AML). The majority of patients who achieve a second remission will ultimately relapse. In this retrospective single-center study, we have analyzed the outcome of patients with a second relapse and tried to define the prognostic factors in intensively treated patients. Of 534 patients with AML, 62 had a second relapse. Thirty-three received further intensive chemotherapy (CT). Eighteen patients (55%) achieved a third complete remission (CR). The early death (ED) rate was only 9%. The overall survival (OS) of treated vs untreated patients was 6.9 vs 1.3 months, respectively (P = 0.01). The major selection criteria for a third CT were a favourable (t(15;17),t(8;21),inv(16)) or normal karyotype, long (>11 months) second CR (P < or = 0.005) and no previous bone marrow transplantation (BMT)(P < 0.01). Favorable or normal karyotype, second CR >11 months, as well as no previous BMT (P < 0.01) were associated with the achievement of a third CR. Favorable (P < 0.005) or normal karyotype (P < 0.01), as well as a second CR >11 months (P < 0.005) were associated with prolonged survival after CT. The median OS for patients receiving CT with favorable or normal cytogenetics, a second CR > 11 months, but no previous BMT was 26.5 months. Five patients with favorable or normal karyotype achieved a fourth or fifth remission. We conclude that intensive CT is associated with a survival benefit and good quality of life if patients are properly selected.