There is a growing need of novel antimicrobial agents specially nano materials against multi drug resistant micro organisms. Especially the bio synthesised nanoparticles become popular as they show lesser or no toxicity and the procedure is environment friendly. Here, at the present study, silver nanoparticles (AgNPs) were obtained through green process using the aqueous yellow petal extract of Butea monosperma lutea Maheswari. The synthesised particles were characterised by UV–visible spectroscopy, Fourier Transform Infra-Red Spectroscopic study (FTIR), X-ray diffraction data (XRD), Scanning Electron Microscopy (SEM), Dynamic light scattering (DLS) and Zeta potential. These together confirm the formation of silver nano particles.