The fabrication and electrical properties of high-density arrays of cylindrical nanoscale capacitors grown in anodic aluminum oxide templates is described. Using chemical vapor deposition, alternating metallic (carbon) and insulating (boron nitride) layers are created within the template pores, thereby forming composite metal/insulator/metal nanotubules. With the metal electrodes evaporated on the two sides of the template, the structure is converted to an array of nanocapacitors connected in parallel. For 50-μm-thick templates, specific capacitances as high as 2.5 μF/cm2 were measured and capacitances as high as 13 μF/cm2 should be attainable by optimizing the insulating layer properties. The fabrication process can be made compatible with the silicon technology and might, therefore, be used to fabricate high-capacitance elements on tightly packed chips. At the same time, the leakage resistance of the arrays fabricated in the preliminary studies reported here is rather low, presumably due to the contamination of the insulating layer. © 2000 American Institute of Physics.