High level of the quality requirements of machined parts is the standard, which is not unique only for automotive industry, but in industry general. The quality of the product surface roughness is key parameter for every machined product, one of the process with the high influence to surface quality is the milling process. In this article is used fuzzy logic to predict the surface quality by milling operation. Based on milling process parameters and measured data, the surface quality will be estimated using the Fuzzy Inference System (FIS). The result shows, that selected fuzzy model can be used to predict surface quality with the selected process parameters. Finally this study can bring cost evaluation during tool selection and machine set up parameters.