A straightforward procedure is described for preparation of arrays of microdisk electrodes comprising bundles of vertically aligned carbon nanotubes (VACNTs). The arrays are fabricated by thermal chemical vapor deposition synthesis directly on a planar carbon film support. Use of standard micro- and nanolithography procedures for patterning the bilayer catalyst spots enables arrays to be grown with controlled electrode diameters and spacings. The minimum accessible VACNT bundle diameter, and hence microelectrode diameter, is 2 µm. After insulating the arrays with SU-8 epoxy and exposing the VACNT ends by polishing or treating with O2 plasma, the microdisk electrodes exhibit attractive electrochemical properties.