During bearing operation under high-load conditions, residual stresses can develop in ball bearing rings. The measurement of these residual stresses is important for understanding the condition of the bearing steel and its development as a result of rolling contact loading. For the measurement of residual stresses in bearing components, laboratory x-ray diffraction is an established tool, and many results have been published in the literature. Measurements of the residual stresses below the raceway surfaces of bearing steels are by nature destructive, and dedicated sample preparation is required in order to measure the material below the surface. This means that the effects of sample preparation on the stress state have to be taken into account. In order to confirm the applicability of sample preparation techniques, synchrotron measurements have been performed in a non-destructive way on tested ball bearings. In this paper, the results of residual stress measurements via synchrotron diffraction are described. The results show good similarity between measurements that were made on prepared samples from a ring with laboratory x-ray diffraction and non-destructive synchrotron measurements. In this way the results of the synchrotron measurements are used to validate the application of laboratory x-ray diffraction techniques for bearing steel investigations.