The occurrence of infectious diseases poses a serious threat to public health globally, particularly with the emergence of antibiotic resistant bacterial strains. Traditionally, organic moieties based antibiotics have been used for the treatment of infectious diseases arising from both community and hospital environments. But, due to the prolonged exposure of bacteria to these antibiotics over the years, they have developed resistance against most of the frequently used antibiotics, through several mechanisms including gene mutation. Inorganic metal oxide nanoparticles may serve as efficient disinfectants owing to their effective antibacterial activity, chemical stability and relatively non-toxic profile. Among metal oxide nanoparticles, iron oxide and zinc oxide demonstrate significant bactericidal activity over a broad range of bacteria primarily by producing reactive oxygen species (ROS) from water and oxygen. In the communicated work, we report the development of a new substitute of conventional antibiotics, which can efficiently combat the multi drug resistant bacteria. Nanoparticles of alpha-Fe2O3, ZnO and Fe/Zn oxide nanocomposites with varying concentrations of Zn were synthesized using wet-chemical method and their structural, magnetic, thermal and biological properties were thoroughly studied. Different characterization techniques such as XRD, FESEM, TEM, EDAX, VSM and TGA-DTA were used to study the physical properties of the prepared materials. The Fe/Zn oxide nanocomposites had exhibited very efficient bactericidal properties against both Gram-positive and Gram-negative bacterial strains. Also, the prepared samples were found to be biocompatible and non-toxic to human cell line MCF7. (C) 2018 Elsevier B.V. All rights reserved.