Objective The aim of this thesis is to investigate the expression and clinical significance of miR-424-5p in patients with acute myeloid leukemia (AML). Methods We selected bone marrow samples from 58 AML patients who visited the Department of Hematology at the Second Affiliated Hospital of Xi’an Jiaotong University from January 2018 to December 2019 as the research sub⁃ jects. Additionally，we collected bone marrow samples from 13 patients with iron-deficiency anemia (IDA) as controls. Real-time quan⁃ titative PCR was used to detect the relative expression of miR-424-5p in the bone marrow samples of both groups. The diagnostic value of miR-424-5p for AML was analyzed using receiver operating characteristic curve (ROC). The expression profile and clinical data of miR-424-5p in 58 AML patients were summarized，and the Kaplan-Meier method was used to analyze the relationship between miR- 424-5p and AML overall survival (OS)，and the correlation between expression level and clinical data. The online database was used to predict the downstream pathways of miR-424-5p and to explore the possible mechanism of miR-424-5p in the pathogenesis of AML. Results MiR-424-5p was significantly downregulated (P = 0.002) in patients with newly diagnosed AML，and its expression level was correlated with age and peripheral blood white cell count (P < 0.05). The area under the ROC curve was 0.776 with a 95% confidence interval of 0.663-0.889，indicating that miR-424-5p could effectively differentiate AML patients from IDA patients. Analysis of clini⁃ cal data showed that the reduced expression level of miR-424-5p was significantly associated with prolonged OS in patients (P = 0.005). The COX proportional hazard model showed that the expression level of miR-424-5p had statistical significance in the model (P < 0.05)，and patients with miR-424-5p expression > 12.478 had a 3.315-fold higher risk of death compared to patients with miR- 424-5p expression ≤ 12.478. Analysis of clinical data revealed a significant correlation between decreased miR-424-5p expression and prolonged OS in patients (P = 0.005). Predictions from the Starbase V2.0 database suggested that the target genes of miR-424-5p may be involved in the occurrence and development of AML through the TRAIL signaling pathway. Conclusion miR-424-5p is downregu⁃ lated in patients with initial AML and has potential as an auxiliary diagnostic marker. Its expression level is associated with age and pe⁃ ripheral blood white cell count in AML patients. Moreover，increased expression of miR-424-5p is significantly correlated with poor prognosis in AML patients and may serve as a potential prognostic indicator.