Cemented carbides are the most common cutting tool materials. To improve machining process, the surface of the cutting tools must be wear resitance with high hardness and chemical inertness. In recent years, several coatings have been developed for tungsten carbide. In this paper, the effect of TiN/TiCN/Al2O3 multicoatings on the performance of drilling process of spherodized cast iron was studied. The external layer is Al2O3 which has high resitance to wear and TiN was chosen as internal layer because of it excellent adhesion to the tungsten carbide surface. The intermediate layer was TiCN because of its compatibility with the other layers. At first, drills were prepared by machining process and then the triple layer coating was applied on the surface of tungsten carbide drills by chemical vapor deposition method. The coating process was performed under usual industrial condition. The thickness of the coatings was 10 micrometers. The wear of drills, the surface roughness and the hole diameter tolerance were investigated. The structure of coating and wear surface was studied by scanning electron microscopy. It was found that the multiple coating significantly improved the wear resistance of the drill compared to uncoated tolls. In addition, it was found that the surface roughness and hole diameter tolerances improved by drilling with coated tools. The reason of this would be the lower wear rate and resulting dimension stability of the coated tools. In addition, according ot wear surface structure, it was concluded that the mechanism of wear was abrasion.