A retrospective analysis was done on 113 patients (median age 73 years) with myelodysplastic syndromes (MDS), consecutively diagnosed at our center during a 10-year period. Patients with refractory anemia (RA) and refractory anemia with ringed sideroblasts (RARS) had significantly longer survival than patients with refractory anemia with excess blasts (RAEB), chronic myelomonocytic leukemia (CMML) or refractory anemia with excess blasts in transformation (RAEB-T). Thirty-seven patients (33%) subsequently developed acute myelogenous leukemia (AML). The percentages of AML transformation for the subgroups were: RA: 26%, RARS: 14%, RAEB: 38%, CMML: 25% and RAEB-T: 69%. A total of 9 patients received high-dose chemotherapy, 7 of them already at the time of MDS diagnosis. Six of the RAEB-T patients entered complete and two partial remission. The median age in the group of RAEB-T patients was significantly lower (62 years) than in the other MDS subgroups. It seems that high-dose chemotherapy, at least in RAEB-T, may induce complete remission and improve survival time.