Several series of Co-Ni/Au multilayers were investigated using different X-ray diffraction methods. The compositions and thicknesses of the Co-Ni layers were varied, and the influence of temperature treatment of gold buffer on the quality of the multilayers was studied. According to the results, the quality of the multilayers is influenced primarily by the roughness of the substrate and the buffer. The Co-Ni/Au multilayer systems grow predominantly with a replicative, highly correlated roughness induced by the substrate and buffer roughness. A cumulative roughness was found only rarely. In contrast, a decrease in the original roughness towards the sample surface was found for certain deposition parameters.