Magnesium oxide (MgO) nanoparticles have garnered significant attention due to their excellent biocompatibility, stability, and diverse biomedical applications, including antimicrobial, antioxidant, anticancer, and antidiabetic properties, as well as uses in tissue engineering, bioimaging, and drug delivery. This review provides a comprehensive overview of the synthesis methods for MgO nanoparticles and their biomedical applications, highlighting their potential mechanisms of action and toxicity profiles. The review emphasizes the importance of developing novel synthetic methods for MgO nanoparticles due to their increasing use in biomedicine. Various synthesis approaches, including co-precipitation, sol-gel, solvothermal/hydrothermal, combustion, and green synthesis, are discussed, along with their advantages and challenges. The review also explores the antimicrobial and antifungal activities of MgO nanoparticles, demonstrating their effectiveness against various bacterial and fungal strains. The mechanisms of action of MgO nanoparticles involve the generation of reactive oxygen species (ROS), disruption of cell membranes, and interference with cellular processes. The review concludes that MgO nanoparticles hold great promise for biomedical applications, with ongoing research aimed at further exploring their potential in the field.Magnesium oxide (MgO) nanoparticles have garnered significant attention due to their excellent biocompatibility, stability, and diverse biomedical applications, including antimicrobial, antioxidant, anticancer, and antidiabetic properties, as well as uses in tissue engineering, bioimaging, and drug delivery. This review provides a comprehensive overview of the synthesis methods for MgO nanoparticles and their biomedical applications, highlighting their potential mechanisms of action and toxicity profiles. The review emphasizes the importance of developing novel synthetic methods for MgO nanoparticles due to their increasing use in biomedicine. Various synthesis approaches, including co-precipitation, sol-gel, solvothermal/hydrothermal, combustion, and green synthesis, are discussed, along with their advantages and challenges. The review also explores the antimicrobial and antifungal activities of MgO nanoparticles, demonstrating their effectiveness against various bacterial and fungal strains. The mechanisms of action of MgO nanoparticles involve the generation of reactive oxygen species (ROS), disruption of cell membranes, and interference with cellular processes. The review concludes that MgO nanoparticles hold great promise for biomedical applications, with ongoing research aimed at further exploring their potential in the field.