This study makes a comparison between whisker-reinforced alumina and SiAlON ceramic tools in high-speed face milling of Inconel 718. A series of tests have been conducted, and the cutting forces, tool wear morphologies and tool failure mechanisms are discussed with regard to a wide range of cutting speeds (500–3000 m/min). Results show that the resultant cutting force of SiAlON ceramic tool KY1540 is much bigger than that of whisker-reinforced alumina ceramic tool KY4300 at the same cutting condition. For both kinds of tools, under relatively lower cutting speed, nose notch wear is the predominant failure mode affecting the tool life, while further increase in the cutting speed, notch wear at the depth of cut becomes the determining factor. KY1540 shows a better notch wear and thermal shock resistance than KY4300. The tool failure mechanisms involve notching, microcracks, chipping, flaking, adhesion and oxidation wear. Better surface quality can be got using KY4300 ceramic tools.