Biomediated silver nanoparticle were synthesized using a cell free extract of a soil bacterium, Exiguobacterium mexicanum PR 10.6. The silver nanoparticles were characterised using UV–Vis spectroscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. The nanoparticles ranged from 5to40 nm. Extracellular polymeric substance played a critical role in the reduction of silver ion and nanoparticle stabilisation when using the cell free extract. The synthesis using E. mexicanum is an effective eco-friendly, rapid method for silver nanoparticle synthesis within 1 h.