OBJECTIVE: Crocin (CRO), the primary antioxidant in saffron, is known for its anticancer properties. However, its effectiveness in topical therapy is limited due to low bioavailability, poor absorption, and low physicochemical stability. This study aimed to prepare crocin nanoparticles (CRO-NPs) to enhance their pharmaceutical efficacy and evaluate the synergistic effects of Cro-NPs with doxorubicin (DOX) chemotherapy on two cell lines: human hepatocellular carcinoma cells (HepG2) and non-cancerous cells (WI38). METHODS: CRO-NPs were prepared using the emulsion diffusion technique and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Zeta potential, and Fourier transform infrared spectroscopy (FT-IR). Cell proliferation inhibition was assessed using the MTT assay for DOX, CRO, CRO-NPs, and DOX+CRO-NPs. Apoptosis and cell cycle were evaluated by flow cytometry, and changes in the expression of apoptotic gene (P53) and autophagic genes (ATG5 & LC3) were analyzed using real-time polymerase chain reaction. RESULTS: TEM and SEM revealed that CRO-NPs exhibited a relatively spherical shape with an average size of 9.3 nm, and zeta potential analysis indicated better stability of CRO-NPs compared to native CRO. Significantly higher antitumor effects of CRO-NPs were observed against HepG2 cells (IC CONCLUSION: Although more in vivo studies in animal models are required to corroborate these results, our findings suggest that CRO-NPs can be a potential new anticancer agent for hepatocellular carcinoma. Moreover, they have a synergistic effect with DOX against HepG2 cells and mitigate the toxicity of DOX on normal WI38 cells.