Background and Aims Hepatocellular carcinoma (HCC) is characterized by high malignancy, invasiveness, and recurrence rates. Identification of novel molecular biomarkers and therapeutic targets is essential for improving patient outcomes. Nudix hydrolase 1 (NUDT1), a key regulator involved in oxidative stress response and DNA damage repair, has been reported to be dysregulated in various cancers; however, its role in HCC remains unclear. This study aimed to investigate the expression pattern, prognostic significance, and biological function of NUDT1 in HCC.Methods RNA sequencing data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and clinical samples were analyzed using bioinformatics approaches to identify HCC-associated genes. The expression level, diagnostic performance, and prognostic value of NUDT1 were evaluated. Immunohistochemistry was performed on 60 paired HCC and adjacent normal tissues to validate NUDT1 expression and analyze its association with clinicopathological characteristics and survival outcomes. Stable NUDT1-knockdown HepG2 cells and NUDT1-overexpressing LM3 cells were established. Cell proliferation, colony formation, migration, invasion, and apoptosis were evaluated using the CCK-8 assay, colony formation assay, wound healing assay, Transwell assay, and flow cytometry. The involvement of the PI3K/Akt signaling pathway was further examined using pathway agonists and inhibitors.Results NUDT1 was significantly upregulated in HCC tissues and was associated with poor overall survival, disease-specific survival, and progression-free interval. Immunohistochemical analysis confirmed increased NUDT1 protein expression in HCC tissues, which was correlated with TNM stage, tumor size, and vascular invasion. Functional assays demonstrated that NUDT1 knockdown inhibited HCC cell proliferation, migration, and invasion while promoting apoptosis, whereas NUDT1 overexpression exerted opposite effects. Mechanistically, activation of the PI3K/Akt pathway partially reversed the inhibitory effects induced by NUDT1 knockdown, while PI3K/Akt inhibition attenuated the tumor-promoting effects of NUDT1 overexpression.Conclusion NUDT1 is highly expressed in HCC and associated with poor prognosis. NUDT1 promotes HCC progression through activation of the PI3K/Akt signaling pathway and may serve as a potential prognostic biomarker and therapeutic target.