Book excerpt: This book describes the biogenic and green synthesis of gold, palladium and platinum nanoparticles through a variety of methods. 80% of the world’s population use traditional medicinal plants as the primary form of healthcare. Biogenic nanoparticles are those particles which are synthesized by biogenic systems like plants, microbes, and fishes. Different plants possess different properties according to their use in fighting against disease. The biological synthesis of metal nanoparticles is mainly a strategy which is employed to protect against toxic and harsh effects that can often arise in the normal synthesis of such particles. The book explains the properties of gold, palladium and platinum metal nanoparticles and discusses the mechanisms behind biological synthesis. It emphasises the basic idea of various syntheses and will, therefore, be of particular support to potential researchers interested in plant synthesis.