Multigram quantities of Cu nanowires ca. 25 nm in diameter and mm in length have been produced by AC electrodeposition into porous aluminium oxide (PAO) templates. Multiple, large-area Al electrodes (5 6 11 cm or 10 6 25 cm) are anodized in parallel at 25.0 V in 0.3 M H 2 SO 4 (aq) using custom built baths. The pores are efficiently filled by applying 200 Hz sine waves at 10 V rms between the anodized Al and Cu plate counter electrodes immersed in a 0.50 M CuSO 4 (aq) solution. Dissolution of the PAO template in 0.6 M H 3 PO 4 to free the Cu nanowires results in significant coarsening of the nanowires, whereas dissolution of the PAO template in 1.0 M NaOH(aq) results in retention of the Cu nanowire diameters corresponding to the pore diameter of the PAO template. Liberated Cu nanowires were characterized by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy.