Nanoparticles (NPs) are usually referred to as particles with a maximum size of 100 nm. NPs exhibit completely new or improved properties compared to larger particles of the bulk material, and these novel properties are derived due to variations in specific characteristics such as size, distribution, and morphology of the particles. A higher surface area to volume ratio is a characteristic feature of NPs. An important area of research in nanotechnology is the biological synthesis of NPs such as nanosilver. Biologically synthesized silver NPs have many applications, such as spectrally selective coatings for solar energy absorption and intercalation material for electric batteries as optical receptor catalysts in chemical reactions, biolabeling. Due to increasing demand for silver NPs, researchers are interested in the field of NP synthesis. Recently, there has been a growing need to develop environmentally benevolent NP synthesis using nontoxic materials in the synthesis protocol. Currently, many researchers are interested in using microorganisms, such as bacteria and fungi, for the synthesis of silver NPs, which play an important role in the remediation of toxic metals through the reduction of metal ions. As soon as the role of bacteria in NP biosynthesis came into the limelight, a lot of metal ions like gold, silver, and cadmium were synthesized in the nano scale. Hence, in this chapter, we have focused on the biosynthesis, purification, and applications of silver NPs.