Optimization is one of the techniques used in manufacturing sectors to arrive for the best manufacturing conditions, and essential need for industries towards manufacturing of quality products at low cost . This paper aims to investigate the optimal set of process parameters such as current , pulse ON time, pulse OFF time, feed rate, wire tension in wire electrical discharge machining (WEDM) process to identify the variations in performance characteristics surface roughness value on the work material for machining Aluminium 6061 using brass electrode. Based on the experiment conducted on L18 orthogonal array, analysis has been carried out using Taguchi method. Response tables and graphs were used to find the optimal levels of parameters in WEDM process. The confirmation experiments were carried out to validate the optimal results. Thus, the machining parameters for WEDM were optimized for achieving lower surface roughness value.