The electrodeposition of the FeCoNiCu quaternary system onto a rotating disk electrode was explored in order to prepare compositionally modulated multilayers. Multilayers having a different layer thickness were electrodeposited by a pulse current method and the structure was determined with transmission electron microscopy and X-ray diffraction. When the multilayer alloy thickness was larger than 10 nm, the deposit grain size was found to be a function of the Co-rich layer thickness. Below an alloy thickness of 10 nm, the Cu layer size was correlated with a preferred deposit orientation. Giant magnetoresistance was also observed for this electrodeposited quaternary system for the first time.