The poly (methyl methacrylate) (PMMA)/Iron-Zinc co-doped nanosized hydroxyapatite (Fe-Zn nHAp) composite films have been prepared by solvent evaporation method. The as prepared composite films were subjected to gamma irradiation at various dosages. Physico-chemical and biological characterization of the composite film were carried out. The XRD, FTIR and SEM analysis confirmed the presence of hydroxyapatite in the PMMA matrix. Irradiated composite films revealed reduced saturation magnetization (42%) and retentivity (66%) due to the defects created on irradiation. The gamma irradiated composite films showed strong antimicrobial activity on gram negative bacteria (E. coil) which may be due to the action of leakage of zinc ions on the surface that block the transport channels of the cell leading to the cell death. Moreover, substantial modification was seen in the hydrophobicity and surface roughness. The irradiations also tend to turn the samples semi conductive. The biocompatibility studies of the gamma irradiated composite films showed enhanced cell viability to NIH 3T3 fibroblast cells. Hence, the gamma irradiated samples showed excellent multifunctional properties that could be used in tissue engineering, bio-sensing and wound healing applications.