A method is presented to determine the coating thickness on a metallic substrate in energy dispersive X-ray fluorescence. The method is based on the measurement of incoherent scattered radiation. Energy dispersive XRF apparatus includes a filtered Am-241 point source and an Si(Li) detector with resolution 160 eV at 5.9 keV. The thicknesses of the coating materials found by the scattered radiation have been compared with thicknesses found by the gravimetric method. The obtained results show that there is good agreement between the present experimental results and the values of the gravimetric method within the estimated experimental error. (C) 2002 Elsevier Science Ltd. All rights reserved.