Due to their easy and low-cost production and enhanced properties, noble metal nanoparticles are preferred as nano-additives in most pharmaceutical compositions. For example, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) possess antiseptic and antimicrobial activity and they are generally preferred for obtaining antibacterial clothing and coatings. In the present study, we report a simple, low cost and green method for synthesizing AgNPs using aqueous extracts of common poppy (Papaver rhoeas L). Synthesised silver nanoparticles were characterised based on Field Emission Scanning Electron Microscopy equipped with energy dispersive X-ray spectroscopy, Fourier-Transform Infrared Spectroscopy, and X-ray diffraction analysis. The synthesised AgNPs were also tested for antimicrobial activity using the agar well diffusion method. Characterisation methods showed that the obtained AgNPs were spherical in shape, with a particle size ranging from 15 to 40 nm. According to the antimicrobial test results, AgNPs effectively inhibited the growth of various gram-positive and gram-negative bacteria. It was concluded that Papaver rhoeas L. extract is effective as a reducing agent for the preparation of stable and monodispersed AgNPs and obtained AgNPs could be useful in antibacterial applications in human and veterinary medicine.