Recent trends in the ornamental industry have increased the use of granite for various decorative applications owing to its outstanding mechanical properties and multicolor. Machining of granites with conventional systems is costly. Therefore, new technologies are being developed for cutting and processing applications of granites. Abrasive waterjet cutting (AWJ) is one of the non-traditional machining processes that have been used extensively in various industrial applications. It enables to cut materials being hard to machine such as steel, ceramic, concrete and stone. However, it may cause roughness and waviness on the cut surface. This significantly affects the dimensional accuracy of the machined part and the quality of surface finish. In this study, optimization of process parameters for surface roughness of two granites cut with abrasive waterjet was carried out based on Taguchi ortogonal design. The conclusions revealed that the abrasive flow rate and traverse speed were the most influential factors on the surface roughness for both granites respectively; followed by standoff distance, water pressure and abrasive size with respect to the granite.