Aluminium based metal matrix composites (MMC) gain its importance in automotive and aerospace applications due to their high strength to low weight ratio, which leads to reduced fuel consumption and improved performance. However the usage of MMC is limited due to its poor machinability. The presence of hard reinforcing particles in MMC makes these materials difficult to machine. A cutting tool with high hardness and low coefficient of friction is required for machining this MMC material effectively. In this paper a comparative study on machinability of different coated tools on LM6 aluminum alloy/alumina MMC are conducted and presented. Experimental results on tool wear, cutting force and surface finish indicate that nano-crystalline diamond coated tools (NCD) outperform the other commercially available coated tools for machining this metal matrix composites. Copyright © 2015 by ASME.