In order to validate the European Prognostic Index (EPI) for patients <or=60 years with acute myeloid leukaemia in first relapse, a cohort of 599 such patients, treated between 1980 and 2004 at the MD Anderson Cancer Center, were assessed using this prognostic index. Three risk groups were defined: favourable, 76 patients (13%) [Overall survival (OS), 64% at 1 year, 22% at 5 years]; intermediate, 137 patients (23%) (OS, 38% at 1 year, 12% at 5 years); and poor, 386 patients (64%) (OS, 17% at 1 year 6% at 5 years). The EPI is reproducible and useful.