The objective of the present work is the investigation of milling process parameters which includes depth of cut, tool diameter, spindle speed, and feed rate resulting in optimal values of the surface roughness during machining of 2024-T4 - AL alloy. The machining operation implemented on XK7124 CNC milling machine. The effects of the selected parameters on the chosen characteristics have been accomplished using Taguchi's parameter design approach; also ANOVA had been used to evaluate the contribution of each parameter on the process outputs.