This study aimed to analyze the factors associated with outcomes of bone marrow transplantation (UR-BMT) or cord blood stem cell transplantation from unrelated donors (UR-CBT). We assessed the time from diagnosis to transplantation among acute myeloid leukemia (AML) patients with intermediate- or poor-risk cytogenetics to identify the potential clinical efficacy of transplantation. We retrospectively analyzed 5331 patients who received UR-BMT or UR-CBT between 2008 and 2017. Patients were divided into four groups according to time from diagnosis to transplantation: (1) UR-BMT and 5 months (n = 2353), (2) UR-BMT and ≤ 5 months (n = 379), (3) UR-CBT and 5 months (n = 1494), and (4) UR-CBT and ≤ 5 months (n = 1106). There was no difference in overall survival (OS) for transplantation at ≤5 months and 5 months in patients with first complete remission for both UR-BMT and UR-CBT, but OS in patients with primary induction failure (PIF) and transplantation at ≤ 5 months was significantly higher in the UR-CBT group compared with that at5 months (P 0.001). Multivariate Cox regression analysis also showed that transplantation at5 months in patients with PIF was an independent predictor of poorer OS. Therefore, UR-CBT at ≤ 5 months after diagnosis is an alternative option for AML patients with PIF.