In pocket milling, a need for optimization of output quality characteristics is necessary for difficult to machine materials such as Ti-6Al-4V due to its applications in dies, molds, aerospace and mechanical industries. This paper shows the incorporation of tool path orientation as a process parameter along with spindle speed, feed rate and depth of cut to improve the output quality characteristics. Optimization was accomplished by varying the one direction tool path orientation together with machining parameters using Taguchi based Grey Relational analysis. The output quality characteristics determined are radial tool deflection, surface roughness and material removal rate (MRR). The optimum combination of process parameters obtained from the grey relational analysis was then validated by performing confirmation tests.