Iron oxide, iron-cobalt core shell nanoparticle and zero valent iron nanoparticles were synthesized by a one pot, room temperature method using co-precipitation, micro emulsion and wet chemical method using gallic acid as the surfactant and reducing agent. The properties and distribution of the particles were confirmed by UV-Visible spectroscopy, dynamic light scattering (DLS) analysis and Scanning Electron Microscopy (SEM). The stability of the particles were evaluated by observation for visible aggregates over a weeks period and progressed for further studies. In this report the anti microbial activities of three different forms of iron namely iron oxide, iron-cobalt composite and zero valent iron were evaluated by zone of inhibition studies by agar well diffusion method on multi drug resistant Staphylococcus aureus sp. The drug kanamycin an amino glycoside antibiotic was used as the positive control for the comparison of the antimicrobial activity. The incubation period of the evaluated microbial inhibition assay was 12 hours from the time on inoculation and well assay. During repeated trials the zone of inhibition remained at high areas proving the particles are toxic to the microbes.