In this study, the machinability of advanced ceramics sintered at three different sintering temperatures is investigated. The results show that although pre-sintered (1300°C/30 min) ceramics can be machined with both carbide tools and ceramic tools, the tools sustain significant levels of tool wear after a very short period of machining. The best overall performance is achieved by using the diamond tool; the latter also being found to be essentially the only tool which can be used to machine the fine-sintered (1500°C/30 min) ceramics. In addition, it is found that when cutting ceramics with a coolant or using a sucker to suck the chip from out of tool face, results in more severe tool wear than does dry cutting. The effect is contrary to that normally expected and would appear to be largely due to the chip discharge not proceeding smoothly. However, when tool face near to the cutting edge is heated and sucked, the tool wear can be improved significantly.