Silver nanoparticles(Ag-NPs) are synthetized successfully by using leaf extract of eucalyptus. The Ag-NPs obtained are characterized by ultraviolet-visible (UV–vis) spectrometer, field emission transmission electron microscopy (FE-TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). FE-TEM analysis revealed the shape of those Ag-NPs being spherical morphologies, with the size range of 4–60nm. FTIR spectrum assumed the polyphenols and proteins act as reducing and stabilizing agents in the synthesis of Ag-NPs.