Objective:The present study is deals with the green synthesis of silver (AgNPs), iron oxide (α-Fe2O3NPs) and core-shell (Ag-α-Fe2O3CNPs) nanoparticles using the aqueous extract ofAlstonia scholariswithout any catalyst, template or surfactant or any intermediate under ultrasound cavitation technique. The purpose was to facilitate the high level of dispersion with increase in rate of reaction. Further AgNPs and α-Fe2O3NPs were used to synthesis Ag-Fe2O3CNPs in aqueous extract ofAlstonia scholarisunder controlled ultrasound cavitation technique.Methods:The size of AgNPs and Ag-Fe2O3CNPs can be tuned by optimizing various reaction parameters. UV-visible, X-ray diffraction spectroscopy (XRD), Transmission electron microscopy (TEM), Field emission scanning electron microscope (FE-SEM) and Fourier transform infra-red spectroscopy has been used for the characterization of silver and core shell Ag@Fe2O3nanoparticles. TEM images clearly show the formation of core shell nanoparticles with spherical morphology.Result:Fourier transform infra-red spectroscopy analysis revealed that carbohydrate, polyphenols, and protein molecules were involved in the synthesis and capping of silver, iron oxide and Ag@Fe2O3CNPs.