The aim of this study is to synthesize and assess the potential applications of rare earth doped cobalt ferrite nanoparticles in cancer treatment through hyperthermia.The synthesis of CoFe2−xRExO4 (where RE=Yb, Dy, Gd and x=0.01–0.3) through the co-precipitation method is presented. The composition and properties of the nanoparticles where investigated and evaluated in correlation with their heat generating capability. The XRD and EDX analysis indicated phase separation for high rare earth content with the appearance of Gd2O3 and Dy2O3 secondary phases, which leads to unwanted changes in the nanoparticles' magnetic properties and consequently of the specific absorption rate. All the nanoparticles present functional group belonging to the surfactant as determined by FT-IR and Raman. Magnetic and specific adsorption rate measurement suggest increases in saturation magnetization and SAR value in doped ferrites, compared to CoFe2O4 with as much as 26% and 15% for Dy doped and Gd doped samples respectively.