Nanotechnology is the most sought field in biomedical research. Metallic nanoparticles have wide applications in the medical field and have gained the attention of various researchers for advanced research for their application in pharmaceutical field. A variety of metallic nanoparticles like gold, silver, platinum, palladium, copper and zinc have been developed so far. There are different methods to synthesize metallic nanoparticles like chemical, physical, and green synthesis methods. Chemical and physical approaches suffer from certain drawbacks whereas green synthesis is emerging as a nontoxic and eco-friendly approach in production of metallic nanoparticles. Green synthesis is further divided into different approaches like synthesis via bacteria, fungi, algae, and plants. These approaches have their own advantages and disadvantages. In this article, we have described various metallic nanoparticles, different modes of green synthesis and brief description about different metabolites present in plant that act as reducing agents in green synthesis of metallic nanoparticles.