In this study, optimization of the burnishing process was carried out to find better performance of burnishing process in CNC machining center using response surface methodology (RSM). The study was conducted on S.G. cast iron component in DOOSAN vertical machining center using internal roller burnishing tools. The internal roller burnishing tool was used in CNC vertical machining center to maintain precise bore size and surface finish. The input parameters were speed, feed, and penetration allowances for burnishing (stock). In this study, the parameter combinations are made using orthogonal L27 array. The optimization was carried out between input and output parameters for the given constraints using RSM. The response surface mathematical model was developed. The interactions between variables were analyzed using response surface plots. The optimized values for burnishing were burnishing speed of 1100 rpm, burnishing feed of 0.113461 mm/rev, and stock of 0.031503 mm. The optimized bore size (31.74 mm), surface roughness (0.3757 lm), and ovality (0.012 mm) were obtained.