BACKGROUND: Aldolase A (ALDOA), a key glycolytic enzyme, has been reported to play an important role in lung, pancreatic, and colorectal cancer. However, the role and mechanism of ALDOA in hepatocellular carcinoma (HCC) are still unclear. This study aimed to study the role and potential mechanism of ALDOA in HCC. METHODS: The changes in expression level and clinical implications of ALDOA in HCC were studied through bioinformatics and online databases. The prognostic role of ALDOA was investigated by Kaplan-Meier and Cox regression survival analysis. We explored the potential mechanism of ALDOA in the development of HCC by gene set enrichment analysis (GSEA). RESULTS: The expression level of ALDOA was significantly increased in HCC compared with adjacent normal tissues (P<0.001). The expression level of ALDOA was significantly associated with tumor, node, metastasis (TNM) stage, histologic grade, and p53 mutation (all P<0.05). Prognostically, HCC patients with high expression of ALDOA indicated poorer prognosis and shorter survival time. In addition, univariate and multivariate Cox regression analysis further suggested that overexpression of ALDOA was an independent prognostic risk factor (P<0.05). Furthermore, the nomogram was developed based on ALDOA expression and tumor TNM stage. Besides, ALDOA DNA copy gain and methylation were associated with ALDOA upregulation in HCC. Finally, GSEA suggested that high expression of ALDOA was associated with glucose catabolic process, cell cycle, DNA replication, E2F1 pathways, protein kinase B/mammalian target of rapamycin (AKT/mTOR) pathways, and CD4 T cell related immune biological processes. CONCLUSIONS: There is a close relationship between ALDOA and HCC progression, and ALDOA may be a novel prognostic biomarker and a promising drug target for the treatment of HCC.