Fe-Al intermetallic coatings have relatively high corrosion resistance, superior electrical resistivity and low thermal conductivity at elevated temperatures under oxidizing atmosphere. In this study, the Fe-Al coatings are fabricated on the steel substrate by mechanical alloying method. The steel substrate surface is hardened and activated as a result of the high-energy impact of balls. Formation of such intermetallic phase increase the local temperature and Fe-Al intermetallic phases are formed in the coating layer. The effects of milling speed, particle size and milling time on thickness of Fe-Al coatings in a planetary ball-mill are investigated by Taguchi method to determine the optimal conditions. Coating thickness is employed as the response to evaluate the effect of the coating parameters. It is found that an increase in the applied milling time and milling speed significantly affected the coating thickness and densification level of the deposited coatings while the particle size is found to be statistically insignificant. The results indicated that the milling time has the most significant contribution (81%) on the coating process while the milling speed time has a lower effect (19 %).