The Kα satellites occur as a group of weak, unresolved lines superimposed on the short wavelength tail of the Kα1 line. Satellite data obtained experimentally with a single‐crystal diffractometer are reported and compared with the results of two‐crystal spectrometer measurements by previous investigators. It is calculated from spectral data that the addition of the satellite group to the Kα1,2 lines shifts the Cu centroid 0.031 xu and the Fe centroid 0.061 xu to shorter wavelengths. The satellites occur superimposed on the short wavelength tail of the Kα1 line in back‐reflection powder line profiles and appear as a low intensity ``plateau'' which may cause difficulties in precision measurements. The effect of the satellite group on the value of the centroid obtained by various methods of truncating the profile is described. The angular separation of the satellites from the Kα1 component increases with increasing diffraction angles and may cause an error of the order of 1% in the relative integrated line intensities if the integration limits do not consistently include or exclude the satellites.