Prognostic factors were studied in a series of 318 patients with acute myeloid leukemia (AML), 17-90 yr old, treated at a single centre during 1982-98, and representing 79% of the total number of cases registered in the area during this period. Risk group stratification based on cytogenetics, occurrence of antecedent hematological disorder, and leukocyte count could be performed in 93%. Five percent were allocated to the favourable risk group, 40% to standard risk, and 55% to adverse risk. Complete remission (CR) was attained in 52%. The CR rate was higher in the favourable (80%) and standard risk groups (69%) than in the adverse risk group (37%). The CR rate increased from 44% in the 1980s to 60% in the 1990s. The 5-yr survival rate for all patients was only 12%. Low age, promyelocytic leukaemia, treatment in the 1990s, high induction treatment intensity, and non-adverse risk group were favourably associated with survival. The median survival time increased from 115 to 349 d between the 1980s and the 1990s, but the 5-yr survival rate was only 11% for patients over 55 yr of age even in the last decade. For the younger patients, the 5-yr overall survival rate increased from 9% to 35% in the last decade. The median time in first remission was 365 d. Age below 56 yr, allogeneic and autologous transplants, and non-adverse risk group were associated with prolonged response duration. The duration of response among all patients increased from 250 d in the 1980s to 451 d in the 1990s, but event-free survival time did not improve significantly in patients above 55 yr of age. Among patients below 56 yr of age, overall survival and event-free survival were significantly better for those who received allogeneic or autologous transplants in first remission than for those who were treated with chemotherapy only. Overall survival times did not improve from the 1980s to the 1990s among those patients below 56 yr who were treated with chemotherapy only in first remission, in spite of the use of transplants in second remission.