Malignant tumors occur by uncontrolled multiplication of the body's cells. Currently, a promising technique, called magnetic hyperthermia, has been intensively researched. The technique makes it possible to interrupt the growth of tumor cells by the localized application of heat from the magnetization/demagnetization of magnetic nanoparticles (the Joule effect). The amount of heat generated depends on the magnetic material and the characteristics of the external magnetic field. In this work, magnetite Fe 3 O 4 particles (core-shell layer type) were synthesized by the wet coprecipitation method and coated with a polymer blend of polyethylene glycol and polyvinylpyrrolidone (PEG/PVP). The nanoparticles were subjected to a magnetic field of intensity equal to 12 kA m −1 and frequency 202 kHz. Under these conditions, specific absorption rate (SAR) values between 15-48 W g −1 were obtained. The heating curves obtained were adjusted with a proposed mathematical model. The adjustments were satisfactory and showed a good correlation coefficient (at an averaged level of 0.99). In addition, hysteresis curves and FTIR spectra were obtained. Keywords Magnetic hyperthermia • Nanoparticles • Magnetite • Mathematical model List of symbols I Electric current, [A] f Frequency, [kHz] t Magnetic field exposure time, [min] ΔT Temperature variation in the hyperthermia assay, [°C]