In this research, non-toxic HfxFe3-xO4 nanoparticles have been proposed for magnetic hyperthermia applications. The effects of Hf amount on the structural, morphological, and magnetic properties of synthesized nanoparticles were studied. Analysis using XRD, TEM, and VSM confirmed the cubic spinel structure of the samples, with sizes below 20 nm and exhibiting superparamagnetic behavior. Different amounts of HfxFe3-xO4 nanoparticles were dispersed in water to examine their applicability for magnetic hyperthermia. The nanoparticles’ nontoxicity was observed through a cell viability analysis of human fibroblasts 1132SK. The findings suggest that the synthesized nanoparticles are effective for magnetic hyperthermia applications.