While many investigations have been performed to establish a better understanding of the effects that magnetic fields and nanoparticles have on cells, the fundamental mechanisms behind the interactions are still yet unknown, and investigations on concurrent exposure are quite limited in scope. This study was therefore established to investigate the biological impact of concurrent exposure to magnetic nanoparticles and extremely-low frequency magnetic fields using an in-vitro CHO-K1 cell line model, in an easily reproducible manner to establish grounds for further in-depth mechanistic, proteomic, and genomic studies. Cells were cultured and exposed to 10nm Fe3O4 nanoparticles, and DC or low frequency (0Hz, 50Hz, and 100Hz) 2.0mT magnetic fields produced by a Helmholtz coil pair. The cells were then observed under confocal fluorescence microscopy, and subject to MTT biological assay to determine the synergistic effects of these concurrent exposures. No effects were observed on cell morphology or microtubule network; however, cell viability was observed to decrease more drastically under the combined effects of magnetic field and nanoparticle exposures, as compared to independent exposures alone. It was concluded that no significant difference was observed between the types of magnetic fields, and their effects on the nanoparticle exposed cells, but quite clearly there are …