In this research, the essential oils obtained from leaves, bulbs and petals of crown imperial plant are used as reducing agents to fabricate silver nanoparticles. The aromatic hydrocarbons, alkenes, ketenes and alkaloids are among the compounds identified in the essential oils as detected by gas chromatography mass spectrometry. The characteristics of silver nanoparticles are investigated by field emission scanning electron microscopy, transmission electron microscopy and XRD. The chemical groups and surface resonance characteristics of the samples are revealed by Fourier transform infrared spectroscopy and UV-Visible spectroscopy, accordingly. The field emission scanning electron microscopy results show that the silver nanoparticles form nanoscale spheres with a mean diameter of 27 +/- 14 nm in case of the sample obtained by essential oil of petals as confirmed by transmission electron microscopy. This sample shows a UV-Visible absorption band at 450 nm. The antibacterial activity of the silver nanoparticles shows a remarkable inhibition capability against all of the tested bacteria, with the sample obtained from petals exhibiting the strongest antibacterial effect in agreement with the obtained minimum inhibitory concentration and minimum bactericidal concentration values. The cell viability assay using Vero cell line reveals a nearly constant viability rate above 125 mu g/mL of silver nanoparticles.