Herein, we report the antimicrobial efficacy of sodium benzoate-functionalized silver nanoparticles synthesized via a simple method and its potential prospects as food preservatives. Sodium benzoate (SB) is a commonly known food preservative and is capable of reducing the silver salt to silver nanoparticles in high yield under facile conditions. The functionalization of SB imparts enough stability to the nanoparticles to remain dispersed in aqueous solution for long time, without the need of any other additional stabilizing agent. The nanoparticles were characterized using high-performance liquid chromatography (HPLC), atomic force microscopy (AFM), zeta potential, Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (H-1-NMR) and UV-visible spectroscopy. In order to explore its role as food preservative, the antimicrobial activity of sodium benzoate-capped silver nanoparticles (SB-SNPs) was tested against various food-borne pathogenic bacteria and the results clearly indicated that the synthesized nanoparticles were highly active against the food pathogen strains even at very low concentrations as compared to sodium benzoate alone.