Surface roughness and cutting velocity are considered as critical machining performance measures in Wire-Electro Discharge Machining (WEDM). In this presentation the results of experiment conducted on 5-axis CNC-WEDM machine on a Ti-6Al-4V alloy will be highlighted. The different setting parameters available on the machine are machining voltage, ignition pulse current, pulse duration, time between two pulses, maximum servo speed variation, servo-control reference voltage, wire speed, wire tension and injection pressure. Many levels of the input variables or parameters must be considered to understand their influence on performance. However, all parameters do not have same degree of influence. Thus experiments are conducted in accordance with Taguchi's L18 Orthogonal Array using three levels to predict the influencing parameters by analysis of variance (ANOVA). Six parameters are identified and experiments are conducted at five different levels for each parameter. The results, findings and observations will be highlighted in this presentation.