Using the data of the patients in complete remission (CR) up to the age of 45 years included in the EORTC-LG/GIMEMA AML-10 trial we investigated the value of the strategy to perform either an autologous (auto-SCT) or an allogeneic (allo-SCT) stem cell transplantation on an intention to treat basis. Between 1993 and 1999, out of 1198 pts, 822 achieved CR. 734 pts, constituting the study group, received an intensieve consolidation course: 293 had a sibling donor and 441 had not. Allo-SCT and auto-SCT was performed in 68.9% and 55.8%, respectively. Cytogenetics was successfully performed in 446 pts. Risk groups were: good (t(8;21), inv(16)), intermediate (NN or -Y only), bad/very bad (all others). Median follow-up was 4 years. The 4-year disease-free survival (DFS) rate of patients with a donor vs of those without a donor was 52.2% vs 42.2%, p = 0.044; the relapse incidence was 30.4% vs 52.5%, death in first complete remission was 17.4% vs 5.3%, and the survival rate was 58.3% vs 50.8% (p = 0.18). The DFS rates in pts with and without a sibling donor were similar in pts with good or intermediate risk cytogenetics, but 43.4% and 18.4%, respectively, in pts with bad or very bad risk cytogenetics. In younger patients (15-35 yrs), the difference was more pronounced. The strategy to perform an allo-SCT in patients where a family donor was available led to better overall results than to perform an auto-SCT, especially for younger patients or those with bad or very bad risk cytogenetics.