The Taguchi method, based on an orthogonal arrangement (L 9 , 3 3 ), the variance analysis, the signal-to-noise ratios and the response surface methodology have been used to optimize maximum flank wear (VB max ) and surface roughness (Ra) of the cutting tool when turning a hardened steel AISI D2 (65 HRC) with PVD-TiAlN coated WC insert upon dry environment. By employing regression models; cutting speed, cutting depth and feed rate, which optimize maximum flank wear and surface roughness were validated. Results of relation signal-to-noise ratios, showed that with cutting speed of 200 m/min, cutting depth of 0.2 mm and feed rate of 0.20 mm/rev, Ra is optimized. With cutting speed of 150 m/min, cutting depth of 0.4 mm and feed rate of 0.3 mm/rev, VB max is optimized. Through the variance analysis it was concluded that the depth of cut was the main parameter that affected on the surface roughness; whereas, the feed rate was the most influential parameter on the flank wear. Confirmation test results showed that the Taguchi method was very successful in the optimization of machining parameters for minimum surface roughness and flank wear in the turning of the D2 steel.