This review article provides a comprehensive overview of magnesium oxide (MgO) nanoparticles, focusing on their synthetic strategies and biomedical applications. MgO nanoparticles have gained significant attention due to their excellent biocompatibility, stability, and diverse biomedical uses, including antimicrobial, antioxidant, anticancer, and antidiabetic properties, as well as applications in tissue engineering, bioimaging, and drug delivery. The article highlights the lack of a comprehensive review on the synthesis methods, biomedical applications, and toxicity assessments of MgO nanoparticles, aiming to address this gap. The review covers various synthetic approaches for producing MgO nanoparticles, including co-precipitation, sol-gel, solvothermal/hydrothermal, combustion, and green synthesis methods. Each method is detailed, emphasizing the advantages and specific conditions required for optimal synthesis. For instance, the co-precipitation method is favored for its high product yield and straightforward procedure, while the sol-gel method offers superior control over the size and shape of nanostructures. Biomedical applications of MgO nanoparticles are extensively discussed, particularly their antibacterial and antifungal activities. Studies show that MgO nanoparticles can effectively combat various bacterial and fungal strains, such as *E. coli*, *S. aureus*, and *Aspergillus niger*. The antibacterial mechanism involves the production of reactive oxygen species (ROS), which cause oxidative stress and damage to bacterial cell membranes, proteins, and nucleic acids. Similarly, the antifungal activity is attributed to the disruption of fungal cell membranes and the production of ROS, leading to cellular death. The review also addresses the potential mechanisms of action and toxicity profiles of MgO nanoparticles, providing insights into their effectiveness and safety. Additionally, it discusses future research directions and challenges, emphasizing the need for further exploration of MgO nanoparticles in biomedical applications. Overall, the article serves as a valuable resource for researchers and practitioners interested in the synthesis and biomedical applications of MgO nanoparticles, offering a detailed understanding of their properties and potential uses.This review article provides a comprehensive overview of magnesium oxide (MgO) nanoparticles, focusing on their synthetic strategies and biomedical applications. MgO nanoparticles have gained significant attention due to their excellent biocompatibility, stability, and diverse biomedical uses, including antimicrobial, antioxidant, anticancer, and antidiabetic properties, as well as applications in tissue engineering, bioimaging, and drug delivery. The article highlights the lack of a comprehensive review on the synthesis methods, biomedical applications, and toxicity assessments of MgO nanoparticles, aiming to address this gap. The review covers various synthetic approaches for producing MgO nanoparticles, including co-precipitation, sol-gel, solvothermal/hydrothermal, combustion, and green synthesis methods. Each method is detailed, emphasizing the advantages and specific conditions required for optimal synthesis. For instance, the co-precipitation method is favored for its high product yield and straightforward procedure, while the sol-gel method offers superior control over the size and shape of nanostructures. Biomedical applications of MgO nanoparticles are extensively discussed, particularly their antibacterial and antifungal activities. Studies show that MgO nanoparticles can effectively combat various bacterial and fungal strains, such as *E. coli*, *S. aureus*, and *Aspergillus niger*. The antibacterial mechanism involves the production of reactive oxygen species (ROS), which cause oxidative stress and damage to bacterial cell membranes, proteins, and nucleic acids. Similarly, the antifungal activity is attributed to the disruption of fungal cell membranes and the production of ROS, leading to cellular death. The review also addresses the potential mechanisms of action and toxicity profiles of MgO nanoparticles, providing insights into their effectiveness and safety. Additionally, it discusses future research directions and challenges, emphasizing the need for further exploration of MgO nanoparticles in biomedical applications. Overall, the article serves as a valuable resource for researchers and practitioners interested in the synthesis and biomedical applications of MgO nanoparticles, offering a detailed understanding of their properties and potential uses.