This article provides a comprehensive review of the toxicological aspects, safety assessment, and green synthesis of Gold Nanoparticles (AuNPs). AuNPs, with sizes ranging from 1 to 100 nm, have gained significant attention due to their versatile applications in various industries, including biomedicine, electronics, and environmental protection. The review highlights the importance of understanding their potential health and environmental impacts, particularly their toxicity. The synthesis of AuNPs involves physical, chemical, and biological methods, with a focus on eco-friendly "green synthesis" approaches. However, physical and chemical methods have limitations, such as high costs and potential toxicity. The biosafety implications of AuNPs are also examined, including their potential toxic effects on cellular, tissue, and organ levels. The safety assessment of AuNPs is crucial for ensuring their safe use in various fields. This process involves in vitro and in vivo studies to investigate immediate and long-term toxicological effects. Green toxicology, an emerging paradigm, emphasizes the design of AuNPs that are inherently safer by incorporating toxicological considerations into the early stages of development. The review also discusses the challenges and limitations of current research, such as the heterogeneity of studies, the predominance of short-term in vitro evaluations, and the lack of standardized synthesis and characterization methods. These limitations highlight the need for ongoing research efforts to standardize methodologies and expand the scope of green toxicology research. In vitro studies on AuNPs reveal that they can induce oxidative stress, DNA damage, and cytotoxicity in various cell lines. In vivo studies show that AuNPs accumulate in the liver and spleen, potentially causing further damage. The impact of AuNPs on immune cells and normal human cell lines, particularly in the nervous, digestive, respiratory, and cardiovascular systems, is also discussed. Overall, the review underscores the need for a thorough understanding of AuNPs' toxicities and the integration of green toxicology principles into their development and application to ensure responsible and sustainable use.This article provides a comprehensive review of the toxicological aspects, safety assessment, and green synthesis of Gold Nanoparticles (AuNPs). AuNPs, with sizes ranging from 1 to 100 nm, have gained significant attention due to their versatile applications in various industries, including biomedicine, electronics, and environmental protection. The review highlights the importance of understanding their potential health and environmental impacts, particularly their toxicity. The synthesis of AuNPs involves physical, chemical, and biological methods, with a focus on eco-friendly "green synthesis" approaches. However, physical and chemical methods have limitations, such as high costs and potential toxicity. The biosafety implications of AuNPs are also examined, including their potential toxic effects on cellular, tissue, and organ levels. The safety assessment of AuNPs is crucial for ensuring their safe use in various fields. This process involves in vitro and in vivo studies to investigate immediate and long-term toxicological effects. Green toxicology, an emerging paradigm, emphasizes the design of AuNPs that are inherently safer by incorporating toxicological considerations into the early stages of development. The review also discusses the challenges and limitations of current research, such as the heterogeneity of studies, the predominance of short-term in vitro evaluations, and the lack of standardized synthesis and characterization methods. These limitations highlight the need for ongoing research efforts to standardize methodologies and expand the scope of green toxicology research. In vitro studies on AuNPs reveal that they can induce oxidative stress, DNA damage, and cytotoxicity in various cell lines. In vivo studies show that AuNPs accumulate in the liver and spleen, potentially causing further damage. The impact of AuNPs on immune cells and normal human cell lines, particularly in the nervous, digestive, respiratory, and cardiovascular systems, is also discussed. Overall, the review underscores the need for a thorough understanding of AuNPs' toxicities and the integration of green toxicology principles into their development and application to ensure responsible and sustainable use.