This work deals with the problem the measuring of form deviations of rotating parts with the use of coordinate measuring machines equipped with a scanning probehead. The authors investigated the influence of the measurement speed and the number of sampling points on the results of the roundness deviation assessment. The experiments were carried out on a Prismo Navigator coordinate measuring machine (Zeiss) equipped with a VAST GOLD XXL head for a scanning speed range of 10 to 60 mm/s and for three different values of sampling points on the roundness profile. The results were compared with reference values obtained from the Taylor Hobson Talyrond 365 instrument. The measurements results were compared both quantitatively (by means of roundness parameter compliance analysis) and qualitatively (by visual analysis of profiles obtained at different scanning speeds). The research showed that the scanning speed can significantly affect the result of the roundness deviation measurement with the use of CMMs.