This chapter focuses on making metal nanoparticles in an environmentally friendly way using plant materials. It talks about how different plants have special chemicals that can help reduce and stabilize these nanoparticles when they’re being made. The mechanisms, influencing factors, and characterisation techniques are discussed in detail. Additionally, the chapter examines the environmental impact and potential applications of these green-synthesized nanoparticles across diverse fields. Overall, it provides a concise and insightful overview, emphasising the importance of sustainable practices in contemporary nanotechnology.