Structural deviations from ideal layering can have a marked effect on the physical properties of multilayers. Using X-ray diffraction and cross-sectional transmission electron microscopy as the structural probes, we have systematically identified the presence of a variety of structural imperfections in sputtered Co/Cu multilayers. By constructing a structural model which realistically represents the multilayer structures, we attempt to extract structural data on the regularity of layering and interfacial roughness through the fitting of low-angle X-ray diffractograms.