Introduction: Cancer is one of the major causes of death around the world. Medicinal plants have been investigated across the world to exploit their potential anticancer activity on a large scale of applications. Objective: The present study is focused on the anticancer activity of the methanolic extract of the medicinal plant, Artemisia Judaica, on Human hepatocellular carcinoma (HepG2) and normal liver (THLE2) cell lines, as well as the mechanisms involved were also investigated. Methods: The collected aerial parts of the plant were extracted by maceration with methanol and the crude extract was collected and stored until use. Cytotoxicity and cell proliferation, cell cycle analysis and the expression level of apoptosis-related genes such as p21, CycB1, CDK1, p53, Bcl-2 and Bax in HepG2 cell lines were estimated using the MTT colourimetric, flow cytometry and quantitative real-time PCR (qRT-PCR) assays, respectively. Results: The results showed that A. Judaica extract (IC50 = 33.76__ampersandsignmu;g/ml) displayed strong cytotoxicity and antiproliferative effect in HepG2 cancer cells. On the other hand, this extract exhibited no cytotoxic activity on the liver normal cell line (THLE2). Flow cytometric analysis of propidium iodide staining revealed that the treatment of HepG2 cells with A. Judaica led to an increase in G2/M phase cell cycle arrest. The qRT-PCR assay revealed that both cyclin B1 (cycB1) and cyclin-dependent kinase (CDK1) genes, as well Bcl-2 showed down-regulation expression levels in HepG2 treated with A. Judaica compared to the untreated cell line. Furthermore, the apoptotic mechanism activated by the plant extract resulted in up-regulation of p53, P21and Bax at mRNA level on HepG2 cell line. Conclusion: These results suggest that A. Judaica could be a promising candidate species as a natural source of anticancer molecules.