Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has improved outcomes in pediatric acute myeloid leukemia (AML), yet post-transplant relapse remains the main barrier to long-term cure. AIMS: To summarize outcomes after first allo-HSCT in pediatric AML and identify clinical and molecular predictors of relapse and survival. Methods: We retrospectively analyzed 452 children with AML receiving first allo-HSCT at the Children’s Hospital of Soochow University (2011–2025). Endpoints were overall survival (OS), event-free survival (EFS), GVHD/relapse-free survival (GRFS), cumulative incidence of relapse (CIR), and non-relapse mortality (NRM). Outcomes were compared by transplant type. Molecular features, induction response, and pre-HSCT morphological remission/MRD status were evaluated. Multivariable models assessed independent prognostic factors. Results: Median age was 90 months (range 4.7–205); 248 were male. Two-year OS, EFS, and GRFS were 83.0% (95% CI 0.794–0.868), 78.9% (0.750–0.830), and 71.9% (0.677–0.764). CIR was 13.37%±3.47% and NRM 9.59%±3.60%. Transplant type was not associated with outcomes. Pre-HSCT morphological remission (P=0.003) and MRD negativity (P80% relapse; KMT2A::AF10 had 19.0% (4/21); spliceosome-mutated AML had 4.2% (1/54). Multivariable analysis identified myeloid sarcoma, M7 phenotype, induction non-response, and pre-HSCT PR/NR as adverse factors, while post-2019 transplantation and younger donor age were protective for relapse-free survival. Conclusions: First allo-HSCT yields favorable survival in pediatric AML, but relapse remains the leading cause of failure. Pre- HSCT disease control and fusion-defined high-risk subtypes (CBFA2T3::GLIS2, TLS::ERG) enable relapse stratification and support intensified relapseprevention strategies.