This paper presents the results of Taguchi DOE (Design of Experiment) investigation to determine the effects of High pressure jet assisted coolant on surface integrity in machining of Inconel 718 aerospace superalloys. Designed experiments were performed under conventional (0.6 MPa) and High pressure jet assisted cooling (15 MPa and 30 MPa) conditions using (Ti,Al)N+TiN coated carbide cutting tool. L-9 (3(4)) Taguchi experimental techniques were used in the analyzing of the machined surface and subsurface: surface roughness measuring device for surface roughness, and X-ray diffraction (XRD) technique was used to determine residual stresses and phase changes induced by conventional and High pressure jet assisted machining coolant. The results show the benefits and the future potential of High pressure jet assisted cooling for surface integrity enhancement to achieve improved product's functional performance in superalloys machining. (C) 2014 The Authors. Published by Elsevier B.V.