High speed end milling of Titanium alloy Ti6Al4V is a potential machining technique for obtaining nano level surface finish using small diameter (2mm and 4mm) tools applying high rpm to facilitate the application of of low values (micro-meter level) of feeda and depth of cut to ensure super finishing that could avoid the need of further grinding and polishing operations. Influences of three cutting parameters, namely cutting speed, axial depth of cut and feed, were analyzed. Mathematical models were developed for output responses Ra and Rt. Analysis of multiple response optimizations of RSM and GA were done to get the best achievable response values. Maximum desirability of 98% was obtained with Ra value of 0.13µm and Rt value of 3.72µm.