Lateral control of template synthesis in nanoporous alumina membranes (NAMs) was previously shown by us to enable preparation of graded composite materials. Formation of thickness gradients of Cu was demonstrated using electrodeposition (or electrodissolution) of Cu in the NAM template under a lateral voltage drop applied to the working electrode. This approach is extended here to the formation of compositional gradients. The latter are achieved by electrochemical co-deposition of two metals (An and Pd) in the membrane pores from a mixed metal-ion solution under a lateral potential drop. to form an alloy that shows a continuous lateral change of the Au/Pd ratio. Environmental scanning electron microscopy images of cross sections along the line of the applied voltage gradient show that the deposit height changes gradually. while local elemental analysis by energy dispersive spectrometry and X-ray diffraction measurements confirm a continuous change of the alloy composition along the membrane matrix.