Résumé : To evaluate the prognostic value of the karyotype in acute myeloblastic leukemia when patients are allocated to have either autologous bone marrow transplantation (BMT) or allogeneic BMT at the time of first remission (CR1), we have prospectively followed 134 consecutive patients from diagnosis. CR was achieved in 118 patients. Allogeneic BMT and autologous BMT were performed in 25 and 43 CR1 patients, respectively. Applying the karyotype classification of Keating et al for remission duration (favorable: t(15;17), inv(16); intermediate: normal, X -Y, t(8;21); unfavorable: other abnormalities), 10 patients had a favorable, 49 an intermediate, and 44 an unfavorable karyotype. The 5-year leukemia-free survival (LFS) probabilities for patients with a good, intermediate and unfavorable karyotype were 65%, 32% and 11%, respectively (log rank test P = 0.0019). The probabilities of relapse were 35% in patients with a favorable karyotype, 52% with an intermediate karyotype and 87% with an unfavorable karyotype (P = 0.0004). In the patients who had autologous BMT in CR1, the LFSs were 100%, 33% and 10% with favorable, intermediate and unfavorable karyotype, respectively (P = 0.04). The karyotype was of no prognostic value in patients receiving allogeneic BMT who had BMT in CR1. This study shows that the karyotype retains its prognostic value when the intentions is to treat patients with acute myeloblastic leukemia in CR1 with BMT. Autologous BMT was not able to improve the poor prognosis associated with an unfavorable karyotype.