question: Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and accounts for the fourth leading cause of all cancer deaths. Scientific evidence has found that plant extracts seem to be a reliable choice due to their multitarget effects against HCC. Juniperus communis has been used for centuries in traditional medicine and has reported its anticancer properties. As a result, the purpose of the study was to investigate the anticancer effect and mechanism of JCo extract on HCC in vitro and in vivo. In this study, we found that J. communis extract (JCo extract) inhibited the growth of human HCC cells by inducing cell cycle arrest at the G0/G1 phase, extensive apoptosis and suppressing metastatic protein expressions in HCC cells. Moreover, the combinational treatment of JCo and VP-16 was found to enhance the anti-cancer effect, revealing that JCo extract might have the potential to be utilized as an adjuvant to promote HCC treatment. Furthermore, in vivo study, JCo extract significantly suppressed HCC tumor growth and extended the lifespan with no or low systemic and pathological toxicity. JCo extract significantly upregulated the expression of pro-apoptotic proteins and tumor suppressor p53, suppressed VEGF/VEGFR autocrine signaling, downregulated cell cycle regulatory proteins and MMP2/MMP9 proteins. Overall, our results provide a basis for exploiting JCo extract as a potential anticancer agent against hepatocellular carcinoma.