In the present study, microwave assisted biogenic synthesis of silver nanoparticles (Ag NPs) was carried out by using aqueous leaf extract of Lepidagathis cristata (L. cristata) which can act itself as a reducing and capping agent. This method was very precious due to their economic and eco-friendly benefits. The microwave assisted biogenic synthesized Ag NPs were characterized and analyzed by various instruments such as ultraviolet-visible spectroscopy (UV-vis), fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDS). The UV-vis absorption spectrum peak at 430 nm, corresponds to the characteristic peak of Ag NPs. The functional biomolecules present in the L. cristata were identified by FT-IR spectroscopy, the XRD analysis explored that the synthesized Ag NPs have high crystallinity, face-centered cubic structure, and spherical shape. Ag NPs properties like size and stability (Zeta potential) of the NPs were calculated by Nano Particle Size Analyzer (NPSA). Further, we evaluated the antibacterial activity of the Ag NPs. The microwave assisted biogenic synthesized Ag NPs to show an excellent antibacterial activity against bacteria’s like Escherichia coli, Pseudomonas aeruginosa (Gram −Ve bacteria), Streptococcus pneumonia (gram +Ve bacteria) and the zone of inhibition range was determined.