The residual stress field in a titanium nitride coating was determined using the X-ray diffraction method based on grazing incident angle geometry. The first order stress components were determined in TiN coating on WC and on steel substrates. The diffraction elastic constants calculated by the self-consistent method were used for the interpretation of the results. The advantages of the grazing incidence geometry are pointed out in the case of the examination of heterogeneous residual stresses in thin layers.