Ti-6Al-4V has an excellent combination of mechanical properties such as high corrosion resistance, low density, high specific strength and low modulus of elasticity, leading this alloy to be widely used in the aerospace industry. However, this alloy is considered a difficult-to-machine material. It was found that the use of thin films deposited on the surface of cutting tools improves the performance and profitability of the process, as well as the machined surface quality, and decreases the resulting wear. Thus, this work aimed to evaluate the wear behaviour of coated cutting tools in the milling of Ti-6Al-4V, varying the cutting speed, cutting length, and feed per tooth. The coating deposited on the cutting tools had a thickness of 1.6 µm, substoichiometric chemical composition, and compact columnar morphology. It was found to belong to the TiAlSiN system. The surface roughness of the machined part, tool wear, and wear mechanisms under the considered conditions were analyzed. It was found that the feed-per-tooth has a strong influence on the wear of the cutting tools and the surface roughness of the machined part. Cutting speed also influence the process, with the increase in this parameter, increasing the flank wear. Regarding the wear mechanisms identified, the wear is predominantly abrasive. Adhesive wear was also observed, mainly for higher feed-per-tooth values. In addition, the cutting edge breakage was observed. Therefore, the wear infringed to the uncoated tools was effectively greater than in the coated tools, at all cutting speeds tested.