The thermal decomposition kinetics of nickel ferrite (NiFe2O4) precursor prepared using egg white solution route in dynamical air atmosphere was studied by means of TG with different heating rates. The activation energy (E α) values of one reaction process were estimated using the methods of Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS), which were found to be consistent. The dependent activation energies on extent of conversions of the decomposition reaction indicate “multi-step” processes. XRD, SEM and FTIR showed that the synthesized NiFe2O4 precursor after calcination at 773 K has a pure spinel phase, having particle sizes of ~54 ± 29 nm.