This project aims to synthesis of nickel ferrite magnetic nanocomposites with non-magnetic coatings to study the antibacterial properties of silver. Non-magnetic materials that are used in this project are as follows: silver nanoparticles, titanium dioxide (TiO 2 ) and poly acrylonitrile co maleic anhydride (PAMA). Five nanocomposites (NiFe 2 O 4 , NiFe 2 O 4 @Ag, NiFe 2 O 4 @PAMA, NiFe 2 O 4 @PAMA@Ag and NiFe 2 O 4 @PAMA@Ag-TiO 2 ) were synthesized and studied. Nickel ferrite nanoparticles were synthesized by the sol-gel method. For the preparation of NiFe 2 O 4 @Ag, NiFe 2 O 4 was coated by Ag and for the synthesis of NiFe 2 O 4 @PAMA@Ag, NiFe 2 O 4 was first covered by PAMA and then silver nanoparticles were immobilized on the surface of the PAMA shell. The structural properties of the nanocomposites were studied using X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FT–IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) techniques. The magnetic properties were investigated by vibrating sample magnetometer (VSM). The antibacterial activity of the nanocomposites was investigated against some gram positive and gram negative bacteria by employing disc diffusion assay. The results show that the antibacterial activity of Ag nanoparticles against all tested bacteria was increased in the order Ag nanoparticles NiFe 2 O 4 @Ag NiFe 2 O 4 @PAMA@Ag–TiO 2 . The results demonstrated that the Ag nanoparticles, when embedded in TiO 2 and combined with NiFe 2 O 4 /PAMA, became an excellent antibacterial agent. Titanium dioxide increases the antibacterial properties of silver nanoparticles. The as–made composite can be readily isolated from aqueous solution via magnetic decantation avoiding contamination of the environment.