In aerospace and nuclear industry, nickel-based alloys are widely used due to their ability to withstand high operating temperature and high resistance to oxidation and corrosion. Poor thermal properties, high strength, tendency to severe work hardening, and high chemical affinity of Iconel 718 makes very difficult to cut. The aim of this study was to evaluate the machinability of Iconel 718 in slot milling operations using titanium aluminium nitride coated solid carbide end mill at different cutting parameters such as cutting speed, feed rate and depth of cut were considered to measure surface roughness and material removal rate.