In this scientific article recommendations for a three-dimensional surface roughness parameter determination of machine elements are developed. As the base of this work the number of surface roughness uncorrelated points, which are defined on the basis of autocorrelation function characteristics, was chosen. The correlation interval and the number of uncorrelated points for roughness sampling length as well as for the roughness average step were calculated. The research was carried out forirregular roughness surfaces, which have been treated by flat grinding, shot peening and electroerosion. As a result, the recommended minimal number of measurement points for reliable 3D roughness parameter determination along the evaluation length was obtained and it draws up 300 points.