Results of the structure characterization of Au/Ni multilayers are presented. The analysis is based on symmetric and asymmetric X-ray diffraction (XRD). Particular attention is paid to interplanar distances and composition profiles of studied multilayers. Symmetric XRD profiles are interpreted using the model of non-ideal superlattice structure based on a Monte Carlo simulation. The model allows to fit experimental profiles starting within a wide range of interplanar distances and avoiding any local minima. Asymmetric XRD measurements were performed for different hkl reflections. A stress analysis was done using sin(2)Psi method. Both asymmetric and symmetric XRD measurements confirm that perpendicular interplanar distances in Au and Ni are larger than the bulk ones. These interplanar distances are discussed in terms of a stress free lattice parameter and a strained one.