Zinc oxide nanoparticles (ZnO NPs) are widely used in various industrial products and have gained significant attention in biomedical applications due to their biocompatibility, low toxicity, and unique properties. This review summarizes the synthesis methods and recent advances of ZnO NPs in biomedical fields, highlighting their potential in anticancer, antibacterial, antidiabetic, anti-inflammatory, and bioimaging applications. ZnO NPs can induce cell apoptosis by generating reactive oxygen species (ROS), releasing zinc ions, and activating apoptotic signaling pathways. They are also effective in drug delivery, with various drugs such as doxorubicin, paclitaxel, and curcumin being loaded onto ZnO NPs for enhanced therapeutic effects. Additionally, ZnO NPs exhibit antibacterial activity by disrupting bacterial cell membranes and inducing ROS production. In diabetes treatment, ZnO NPs have shown potential due to their ability to enhance insulin activity and reduce blood glucose levels. ZnO NPs also demonstrate anti-inflammatory properties by suppressing pro-inflammatory cytokines and reducing oxidative stress. For bioimaging, ZnO NPs exhibit luminescent properties, making them suitable for fluorescent imaging. Despite their promising applications, challenges remain in understanding the long-term biological effects and toxicity of ZnO NPs. Future research should focus on improving their safety, efficacy, and understanding of their mechanisms in biomedical applications.Zinc oxide nanoparticles (ZnO NPs) are widely used in various industrial products and have gained significant attention in biomedical applications due to their biocompatibility, low toxicity, and unique properties. This review summarizes the synthesis methods and recent advances of ZnO NPs in biomedical fields, highlighting their potential in anticancer, antibacterial, antidiabetic, anti-inflammatory, and bioimaging applications. ZnO NPs can induce cell apoptosis by generating reactive oxygen species (ROS), releasing zinc ions, and activating apoptotic signaling pathways. They are also effective in drug delivery, with various drugs such as doxorubicin, paclitaxel, and curcumin being loaded onto ZnO NPs for enhanced therapeutic effects. Additionally, ZnO NPs exhibit antibacterial activity by disrupting bacterial cell membranes and inducing ROS production. In diabetes treatment, ZnO NPs have shown potential due to their ability to enhance insulin activity and reduce blood glucose levels. ZnO NPs also demonstrate anti-inflammatory properties by suppressing pro-inflammatory cytokines and reducing oxidative stress. For bioimaging, ZnO NPs exhibit luminescent properties, making them suitable for fluorescent imaging. Despite their promising applications, challenges remain in understanding the long-term biological effects and toxicity of ZnO NPs. Future research should focus on improving their safety, efficacy, and understanding of their mechanisms in biomedical applications.