Incident primary beam divergence is a source of systematic error in X-ray standing wave (XSW) characterization of single and multilayer thin films. Primary beam divergence significantly alters the XSW profile of a layered material and can lead to large errors when used with higher excitation energies. The present study suggests that when one uses Mo-Kα excitation, the primary beam divergence should be in range of 0.005 0 . On the other hand, in the case of Cu-Kα excitation, primary beam divergence can be relaxed up to 0.01 0 .