This research work focuses on the impact of graphite addition to the Al/SiC hybrid metal matrix composites manufactured by stir casting process. Three specimens were prepared with Al6061 alloy + 5 wt. % SiC and varying weight percent of graphite. Al6061 matrix material is suitable for machining and welding applications commonly used in construction of aircraft wings and fuselages. Machining of composite materials is often required to meet dimensional tolerances, surface roughness and to create holes. A layered SiC/Gr composite material is used in gas turbine combustor can. Machining of Al/SiC/Gr hybrid composite was done in Esteem ETM 356 lathe using tungsten carbide insert. Optimization of three machining parameters cutting speed, feed rate and depth of cut, was done using four levels. From ANOVA results feed rate (35.83%) is the important factor influencing surface roughness. Grey Relational analysis was done for simultaneous improvement of Material Removal Rate and surface roughness. © 2020, Faculty of Mechanical Engineering, Belgrade.