Abstract Nanotechnology has a great importance in various industries including pharma, food, textile, and cosmetics etc. To minimize the level of hazardous waste production by chemical and physical synthesis modes, there is a need to develop an eco-friendly method which is efficient, cost effective, non-toxic and industrious. Therefore, green synthesis method involving plants and plant metabolites becomes advantageous in many aspects over other methods of synthesis. During the study, green method was used to synthesise the silver nanoparticles (AgNPs) by using aqueous leaf extract of Nyctanthes arbor-tristis. Further, the resultant AgNPs were confirmed and characterized using different analytical techniques comprising UV–visible spectroscopy, Fourier transform infrared spectroscopy, zeta potential, particle size analyzer and scanning electron microscopy. UV–visible spectroscopic analysis for various plant extract and silver nitrate concentrations revealed formation of spectral peaks at 450–480 nm range, confirming successful fabrication of AgNPs and the FTIR spectra ensured the involvement of plant metabolites in biological reduction of silver nitrate as well as stabilization of synthesized AgNPs. Scanning electron microscopy images revealed the synthesis of spherical AgNPs ranges between 40 and 60 nm. Stability of these AgNPs was ensured by negative values of zeta potential ranges (−19.7 to −19.2). Furthermore, synthesized AgNPs showed effective antimicrobial efficiencies against Escherichia coli (E. coli.), Staphylococcus aureus (S. aureus) and Shewanella putrification (S. putrification).