Present study has been designed to govern the usage of nanocomposite of Si3N4 with trimetallic oxide nanoparticles of Ag, Mg and Fe (AgO/MgO/FeO@Si3N4) for the tetracycline (TC) removal from aqueous solution. Characterization techniques such as SEM, TEM, XRD, FTIR, XPS and BET were employed for analysing the successful fabrication of AgO/MgO/FeO@Si3N4 nanocomposite. Adsorption process has been found to be dependent upon the surface properties of AgO/MgO/FeO@Si3N4 nanocomposite (such as charge, functionality, etc), concentration of TC, solution pH and contact time. As determined from the isotherm studies, surface of AgO/MgO/FeO@Si3N4 nanocomposite has been found to be energetically heterogeneous in nature as the data fitted well to Freundlich isotherm. Maximum adsorption capacity of AgO/MgO/FeO@Si3N4 nanocomposite has been found to be 172.41 mg/g. Pseudo-second order kinetic model successfully explained the rate studies of TC adsorption. Also, reusability study of AgO/MgO/FeO@Si3N4 nanocomposite has also been carried out. In short, the present study could determine an effective way for the removal of toxic pollutants from the wastewater system. (C) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.