Gold Nanoparticles (AuNPs) have gained significant attention due to their versatile applications in various fields, including biomedicine, electronics, and environmental science. However, their potential health and environmental impacts necessitate thorough toxicological evaluation. This review critically examines the synthesis methods, toxicological profiles, and safety assessments of AuNPs, emphasizing the importance of green synthesis approaches to minimize adverse effects. The review highlights the critical role of nanoparticle size, shape, and surface properties in determining their biological behavior and toxicity. Smaller AuNPs can penetrate biological barriers more easily, leading to cellular damage, genotoxicity, and inflammatory responses. In vitro studies reveal that AuNPs induce oxidative stress, DNA damage, and cytotoxicity in various cell types, including immune cells and human cell lines. In vivo studies show that AuNPs accumulate in the liver and spleen, potentially causing organ toxicity. The review also discusses the impact of AuNPs on the nervous, digestive, and respiratory systems, with findings indicating potential neurotoxicity, cytotoxicity in intestinal cells, and effects on lung tissue. The integration of green toxicology principles is crucial for developing safer and more sustainable AuNPs. The review underscores the need for standardized methodologies, long-term studies, and regulatory frameworks to ensure the safe application of AuNPs. Overall, the review emphasizes the balance between the benefits of AuNPs and the potential risks they pose to human health and the environment.Gold Nanoparticles (AuNPs) have gained significant attention due to their versatile applications in various fields, including biomedicine, electronics, and environmental science. However, their potential health and environmental impacts necessitate thorough toxicological evaluation. This review critically examines the synthesis methods, toxicological profiles, and safety assessments of AuNPs, emphasizing the importance of green synthesis approaches to minimize adverse effects. The review highlights the critical role of nanoparticle size, shape, and surface properties in determining their biological behavior and toxicity. Smaller AuNPs can penetrate biological barriers more easily, leading to cellular damage, genotoxicity, and inflammatory responses. In vitro studies reveal that AuNPs induce oxidative stress, DNA damage, and cytotoxicity in various cell types, including immune cells and human cell lines. In vivo studies show that AuNPs accumulate in the liver and spleen, potentially causing organ toxicity. The review also discusses the impact of AuNPs on the nervous, digestive, and respiratory systems, with findings indicating potential neurotoxicity, cytotoxicity in intestinal cells, and effects on lung tissue. The integration of green toxicology principles is crucial for developing safer and more sustainable AuNPs. The review underscores the need for standardized methodologies, long-term studies, and regulatory frameworks to ensure the safe application of AuNPs. Overall, the review emphasizes the balance between the benefits of AuNPs and the potential risks they pose to human health and the environment.