The isothermal oxidation behaviour of FeAlCrZrB intermetallic in air over the temperature range of 700–1100°C was studied. Characterisation of the specimens after oxidation was conducted using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The rate constants of the isothermal oxidation and activation energies for oxide layer growth were determined. Limited scale spallation was observed in the specimens oxidised at 1100°C. Scale failure for these specimens results from the high thermal stresses induced during the cooling stage after oxidation.