The interaction of thiabendazole (Tbz) with hemoglobin (Hb) on epoxy-functionalized iron oxide nanoparticles was presented in this study. The binding capacity of Tbz was determined by measuring at an excitation wavelength of 299 nm using fluorescence spectroscopy. The thermodynamic parameters of the Hb-Tbz interaction were calculated from Stern-Volmer and van't Hoff equations. The values of enthalpy change, δH, and entropy change, δS, were found to be 0.20 kJ mol^{- 1} and 0.70 J mol^{- 1} K^{- 1}, respectively, which indicates that the hydrophilic interaction plays a main role in the binding process. The interaction ability was confirmed by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Also, the thermal behavior of the Hb-Tbz interaction on functionalized iron oxide nanoparticles was studied by using the thermogravimetric analysis (TGA) technique in the temperature range of 25-950 °C, and then the kinetic parameters for the thermal decomposition were determined using the Horowitz-Metzger method.